drivers: renesas: rpc: Move to common

Move rpc driver code to common directory, so that the same
code can be re-used by both R-Car Gen3 and RZ/G2 platforms.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Change-Id: I04805d720d95b8edcc14e652f897fadc7f432197

plat/renesas/common/common.mk

@@ -85,6 +85,7 @@ BL2_SOURCES	+=	${RCAR_GIC_SOURCES}				\
 			drivers/renesas/common/io/io_memdrv.c		\
 			drivers/renesas/common/io/io_rcar.c		\
 			drivers/renesas/common/auth/auth_mod.c		\
+			drivers/renesas/common/rpc/rpc_driver.c		\
 			drivers/renesas/common/dma/dma_driver.c		\
 			drivers/renesas/common/avs/avs_driver.c		\
 			drivers/renesas/common/delay/micro_delay.c	\

plat/renesas/rcar/platform.mk

@@ -320,7 +320,6 @@ BL2_SOURCES	+=	plat/renesas/rcar/aarch64/platform_common.c	\
 			plat/renesas/rcar/bl2_plat_mem_params_desc.c	\
 			plat/renesas/rcar/plat_image_load.c		\
 			plat/renesas/rcar/bl2_cpg_init.c		\
-			drivers/renesas/rcar/rpc/rpc_driver.c		\
 			drivers/renesas/rcar/board/board.c
 
 BL31_SOURCES	+=	plat/renesas/rcar/plat_topology.c		\