clk: renesas: r8a779h0: Add SDHI clock

Add the SDHI module clock, which is used by the SD Card/MMC Interface on
the Renesas R-Car V4M (R8A779H0) SoC.

Signed-off-by: Cong Dang <cong.dang.xn@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/3a604a6924043775c2ed0630b1c5c29be2d1a5b9.1707915642.git.geert+renesas@glider.be