pinctrl: sh-pfc: r8a7796: Fix to delete A20..A25 pins function definitions

pinctrl: sh-pfc: r8a7796: Fix to delete A20..A25 pins function definitions

This patch fixes the macro definitions of A20..A25 pins function deleted.

This is a correction because IPSR register specification for R8A7796 SoC
was changed in R-Car Gen3 Hardware User's Manual Rev.0.53E.

Fixes: f9aece7344bd81ce ("pinctrl: sh-pfc: Initial R8A7796 PFC support")
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>