ARM: renesas: Rename common/common.c to common/rcar64-common.c

The common.c content is specific to 64-bit R-Car SoCs, rename
the file to rcar64-common.c and remove R-Car 64-bit ifdeffery
in the file. No functional change.

Reviewed-by: Quentin Schulz <quentin.schulz@cherry.de>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/board/renesas/common/Makefile b/board/renesas/common/Makefile
index c531738..8c26c0a 100644
--- a/board/renesas/common/Makefile
+++ b/board/renesas/common/Makefile
@@ -18,7 +18,7 @@
 # 64 bit SoCs
 ifdef CONFIG_RCAR_64
 ifndef CONFIG_XPL_BUILD
-obj-y	+= common.o
+obj-y	+= rcar64-common.o
 endif
 
 ifdef CONFIG_RCAR_GEN3