Rename Cortex Hercules Files to Cortex A78

This should allow git to easily track file moves

Signed-off-by: Jimmy Brisson <jimmy.brisson@arm.com>
Change-Id: I1592cf39a4f94209c560dc6d1a8bc1bfb21d8327
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index 33531f3..024e682 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -129,10 +129,10 @@
 		FVP_CPU_LIBS	+=	lib/cpus/aarch64/cortex_a76.S		\
 					lib/cpus/aarch64/cortex_a76ae.S		\
 					lib/cpus/aarch64/cortex_a77.S		\
+					lib/cpus/aarch64/cortex_a78.S		\
 					lib/cpus/aarch64/neoverse_n1.S		\
 					lib/cpus/aarch64/neoverse_e1.S		\
 					lib/cpus/aarch64/neoverse_zeus.S	\
-					lib/cpus/aarch64/cortex_hercules.S	\
 					lib/cpus/aarch64/cortex_hercules_ae.S	\
 					lib/cpus/aarch64/cortex_klein.S	        \
 					lib/cpus/aarch64/cortex_matterhorn.S	\