pinctrl: renesas: r8a779h0: Add SCIF_CLK pins, groups, functions

Add pins, groups and functions for the baud rate generation clock pins
(SCIF_CLK) 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>
Link: https://lore.kernel.org/r/ee056d78d3a339bdbcca2cc5281f1fe01bbc3953.1706264667.git.geert+renesas@glider.be