pinctrl: renesas: r8a779h0: Add INTC-EX pins, groups, and function

Add pins, groups, and function for the Interrupt Controller for External
Devices (INTC-EX) on the Renesas R-Car V4M (R8A779H0) SoC.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/258d03b27b77f60cc03fc3257bb4c6715b612a61.1713282028.git.geert+renesas@glider.be