pinctrl: rzg2l: Drop unnecessary scope

In rzg2l_pinconf_set(), there are no new variables defined in the case
statement for PIN_CONFIG_INPUT_ENABLE so no additional scope is needed.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>