fvp: Increase stack size when SPM is enabled

Change-Id: Iec265dc85d44f35048d1fbcfbe55960d45570027
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

plat/arm/board/fvp/include/platform_def.h

@@ -153,7 +153,7 @@
 # define PLATFORM_STACK_SIZE		UL(0x400)
 #elif defined(IMAGE_BL31)
 # if ENABLE_SPM
-#  define PLATFORM_STACK_SIZE		UL(0x500)
+#  define PLATFORM_STACK_SIZE		UL(0x600)
 # elif PLAT_XLAT_TABLES_DYNAMIC
 #  define PLATFORM_STACK_SIZE		UL(0x800)
 # else