pinctrl: sh-pfc: r8a7795: Fix MOD_SEL2 bit26 to 0x0 when using SCK5_A

This patch fixes the implementation incorrect of MOD_SEL2 bit26 value
when SCK5_A pin function is selected for IPSR16 bit[31:28].

This is a correction to the incorrect implementation of MOD_SEL register
pin assignment for R8A7795 ES2.0 SoC specification of R-Car Gen3 Hardware
User's Manual Rev.0.51E or later.

Fixes: b205914c ("pinctrl: sh-pfc: r8a7795: Add support for R-Car H3 ES2.0")
Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com>
Signed-off-by: Yoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>