CI: allow jobs to be run in merge requests

Out-of-tree users could run an out-of-tree CI with limited coverage,
however it is convenient to be able to run the upstream CI from time
to time. To enable that we would need to change job rules to be able
to run on any GitLab event. Excerpt from GitLab documentation:

> Jobs with no rules default to except: merge_requests

Signed-off-by: Andrejs Cainikovs <andrejs.cainikovs@toradex.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

.gitlab-ci.yml

@@ -21,6 +21,8 @@ stages:
 .buildman_and_testpy_template: &buildman_and_testpy_dfn
   stage: test.py
   retry: 2 # QEMU may be too slow, etc.
+  rules:
+    - when: always
   before_script:
     # Clone uboot-test-hooks
     - git config --global --add safe.directory "${CI_PROJECT_DIR}"
@@ -93,8 +95,13 @@ stages:
       - "*.css"
     expire_in: 1 week
 
-build all 32bit ARM platforms:
+.world_build:
   stage: world build
+  rules:
+    - when: always
+
+build all 32bit ARM platforms:
+  extends: .world_build
   script:
     - ret=0;
       git config --global --add safe.directory "${CI_PROJECT_DIR}";
@@ -106,7 +113,7 @@ build all 32bit ARM platforms:
       fi;
 
 build all 64bit ARM platforms:
-  stage: world build
+  extends: .world_build
   script:
     - virtualenv -p /usr/bin/python3 /tmp/venv
     - . /tmp/venv/bin/activate
@@ -120,7 +127,7 @@ build all 64bit ARM platforms:
       fi;
 
 build all PowerPC platforms:
-  stage: world build
+  extends: .world_build
   script:
     - ret=0;
       git config --global --add safe.directory "${CI_PROJECT_DIR}";
@@ -131,7 +138,7 @@ build all PowerPC platforms:
       fi;
 
 build all other platforms:
-  stage: world build
+  extends: .world_build
   script:
     - ret=0;
       git config --global --add safe.directory "${CI_PROJECT_DIR}";
@@ -141,8 +148,13 @@ build all other platforms:
         exit $ret;
       fi;
 
-check for new CONFIG symbols outside Kconfig:
+.testsuites:
   stage: testsuites
+  rules:
+    - when: always
+
+check for new CONFIG symbols outside Kconfig:
+  extends: .testsuites
   script:
     - git config --global --add safe.directory "${CI_PROJECT_DIR}"
     # If grep succeeds and finds a match the test fails as we should
@@ -153,7 +165,7 @@ check for new CONFIG symbols outside Kconfig:
 
 # build documentation
 docs:
-  stage: testsuites
+  extends: .testsuites
   script:
     - virtualenv -p /usr/bin/python3 /tmp/venvhtml
     - . /tmp/venvhtml/bin/activate
@@ -163,20 +175,20 @@ docs:
 
 # ensure all configs have MAINTAINERS entries
 Check for configs without MAINTAINERS entry:
-  stage: testsuites
+  extends: .testsuites
   script:
     - ./tools/buildman/buildman --maintainer-check || exit 0
 
 # Ensure host tools build
 Build tools-only and envtools:
-  stage: testsuites
+  extends: .testsuites
   script:
     - make tools-only_config tools-only -j$(nproc);
       make mrproper;
       make tools-only_config envtools -j$(nproc)
 
 Run binman, buildman, dtoc, Kconfig and patman testsuites:
-  stage: testsuites
+  extends: .testsuites
   script:
     - git config --global user.name "GitLab CI Runner";
       git config --global user.email trini@konsulko.com;
@@ -200,7 +212,7 @@ Run binman, buildman, dtoc, Kconfig and patman testsuites:
       make testconfig
 
 Run tests for Nokia RX-51 (aka N900):
-  stage: testsuites
+  extends: .testsuites
   script:
     - mkdir nokia_rx51_tmp;
       ln -s /opt/nokia/u-boot-gen-combined nokia_rx51_tmp/;
@@ -214,7 +226,7 @@ Run tests for Nokia RX-51 (aka N900):
 
 # Check for any pylint regressions
 Run pylint:
-  stage: testsuites
+  extends: .testsuites
   script:
     - git config --global --add safe.directory "${CI_PROJECT_DIR}"
     - pip install -r test/py/requirements.txt
@@ -234,7 +246,7 @@ Run pylint:
 
 # Check for pre-schema driver model tags
 Check for pre-schema tags:
-  stage: testsuites
+  extends: .testsuites
   script:
     - git config --global --add safe.directory "${CI_PROJECT_DIR}";
     # If grep succeeds and finds a match the test fails as we should
@@ -243,7 +255,7 @@ Check for pre-schema tags:
 
 # Check we can package the Python tools
 Check packing of Python tools:
-  stage: testsuites
+  extends: .testsuites
   script:
     - make pip