pinctrl: renesas: rzg2l: Return -EINVAL for pins which have input disabled

Pin status reported by pinconf-pins file always reported pin status as
"input enabled" even for pins which had input disabled. Fix this by
returning -EINVAL for the pins which have input disabled.

Fixes: c4c4637e

 ("pinctrl: renesas: Add RZ/G2L pin and gpio controller driver")
Reported-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Phil Edworthy <phil.edworthy@renesas.com>
Link: https://lore.kernel.org/r/20220511094057.3151-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>