Modify FVP makefile for cores that support both AArch64/32

Some cores support only AArch64 from EL1 and above, e.g. A76, N1 etc. If
TF-A is compiled with CTX_INCLUDE_AARCH32_REGS=0 so as to properly
handle those cores, only the AArch64 cores' assembly is included in the
TF-A binary. In other words, for FVP, TF-A assumes that AArch64 only
cores will never exist in the same cluster with cores that also support
AArch32.

However, A55 and A75 can be used as AArch64 only cores, despite
supporting AArch32, too. This patch enables A55 and A75 to exist in
clusters together with AArch64 cores.

Change-Id: I58750ad6c3d76ce77eb354784c2a42f2c179031d
Signed-off-by: John Tsichritzis <john.tsichritzis@arm.com>

plat/arm/board/fvp/platform.mk

@@ -99,14 +99,16 @@ ifeq (${ARCH}, aarch64)
 # select a different set of CPU files, depending on whether we compile for
 # hardware assisted coherency cores or not
 ifeq (${HW_ASSISTED_COHERENCY}, 0)
+# Cores used without DSU
 	FVP_CPU_LIBS	+=	lib/cpus/aarch64/cortex_a35.S			\
 				lib/cpus/aarch64/cortex_a53.S			\
 				lib/cpus/aarch64/cortex_a57.S			\
 				lib/cpus/aarch64/cortex_a72.S			\
 				lib/cpus/aarch64/cortex_a73.S
 else
-	# AArch64-only cores
+# Cores used with DSU only
 	ifeq (${CTX_INCLUDE_AARCH32_REGS}, 0)
+	# AArch64-only cores
 		FVP_CPU_LIBS	+=	lib/cpus/aarch64/cortex_a76.S		\
 					lib/cpus/aarch64/cortex_a76ae.S		\
 					lib/cpus/aarch64/cortex_a77.S		\
@@ -114,11 +116,10 @@ else
 					lib/cpus/aarch64/neoverse_e1.S		\
 					lib/cpus/aarch64/neoverse_zeus.S	\
 					lib/cpus/aarch64/cortex_hercules.S
-	# AArch64/AArch32
-	else
-		FVP_CPU_LIBS	+=	lib/cpus/aarch64/cortex_a55.S		\
-					lib/cpus/aarch64/cortex_a75.S
 	endif
+	# AArch64/AArch32 cores
+	FVP_CPU_LIBS	+=	lib/cpus/aarch64/cortex_a55.S		\
+				lib/cpus/aarch64/cortex_a75.S
 endif
 
 else