pinctrl: sh-pfc: r8a7795: Add MSIOF pins, groups and functions

Add pins, groups, and functions for MSIOF on R-Car H3 ES2.0.

Extracted from a big patch in the BSP by Takeshi Kihara, with
corrections for MSIOF3 SS1_E/SS2_E pins and SS2_E mux.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>