ddr: altera: include u-boot/schedule.h

These TUs currently rely on getting a declaration of schedule()
through some nested include. Include the proper header directly.

Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

drivers/ddr/altera/sdram_n5x.c

@@ -22,6 +22,7 @@
 #include <asm/io.h>
 #include <linux/err.h>
 #include <linux/sizes.h>
+#include <u-boot/schedule.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 

drivers/ddr/altera/sdram_soc64.c

@@ -24,6 +24,7 @@
 #include <asm/io.h>
 #include <dm/device_compat.h>
 #include <linux/sizes.h>
+#include <u-boot/schedule.h>
 
 #define PGTABLE_OFF	0x4000