pinctrl: renesas: rzg2l: Update PIN_CFG_MASK() macro to be 32-bit wide

Modify the `PIN_CFG_MASK()` macro to be 32-bit wide. The current maximum
value for `PIN_CFG_*` is `BIT(21)`, which fits within a 32-bit mask.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240618174831.415583-2-prabhakar.mahadev-lad.rj@bp.renesas.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>