mmc: host: Kconfig: Make MMC_SDHI_INTERNAL_DMAC config option dependant on ARCH_RENESAS

MMC_SDHI_INTERNAL_DMAC config option has dependency on ARM64 and
R7S9210/R8A77470 this dependency will keep growing for future SoCs for
varying architectures. So to simplify this configuration make
MMC_SDHI_INTERNAL_DMAC solely depend on ARCH_RENESAS, as all Renesas
SoCs inherently depend on the ARCH_RENESAS config option.

This allows selecting MMC_SDHI_INTERNAL_DMAC config option for RZ/Five SoC
which is based on RISC-V architecture.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20230901122701.318082-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>