Merge changes from topic "od/hf-doc-migration" into integration

* changes:
  docs(spm-mm): remove reference to SEL2 SPMC
  docs: remove SEL2 SPMC threat model
  docs: remove unused SPM related diagrams

docs/components/secure-partition-manager-mm.rst

@@ -4,17 +4,10 @@ Secure Partition Manager (MM)
 Foreword
 ========
 
-Two implementations of a Secure Partition Manager co-exist in the TF-A codebase:
+This document describes the implementation where the Secure Partition Manager
-
+resides at EL3 and management services run from isolated Secure Partitions at
--  SPM based on the FF-A specification (:ref:`Secure Partition Manager`).
+S-EL0. The communication protocol is established through the Management Mode
--  SPM based on the MM interface.
+(MM) interface.
-
-Both implementations differ in their architectures and only one can be selected
-at build time.
-
-This document describes the latter implementation where the Secure Partition Manager
-resides at EL3 and management services run from isolated Secure Partitions at S-EL0.
-The communication protocol is established through the Management Mode (MM) interface.
 
 Background
 ==========

docs/threat_model/index.rst

@@ -31,7 +31,6 @@ data flow diagram, as well as a list of threats we have identified using the
    :caption: Contents
 
    threat_model
-   threat_model_spm
    threat_model_el3_spm
    threat_model_fvp_r
    threat_model_rss_interface