rcar_gen3: plat: Staticize memory maps
rcar_gen3: plat: Staticize memory maps

Staticize the platform memory map tables as they are only used within
the platform_common.c file.

Signed-off-by: Marek Vasut <bcf2901fa1b128a7a3f88ee031c46807a29aa29d@gmail.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware