pinctrl: renesas: rzg2l: Fix OEN resume

pinctrl: renesas: rzg2l: Fix OEN resume

Writing to the PFC_OEN register is controlled by the write protect
register (PWPR).  Currently the OEN register write in resume() is done
without enabling write access in PWPR leading to incorrect operation.

Fixes: cd39805be85b ("pinctrl: renesas: rzg2l: Unify OEN handling across RZ/{G2L,V2H,V2N}")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
[geert: Move spin_*lock*() calls inside if-statements]
Link: https://lore.kernel.org/20250817143024.165471-2-biju.das.jz@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>