mmc: renesas-sdhi: Fix error handling in rzg2l_sdhi_setup

We should ensure that reset_free() is called in the error path.

Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Fixes: 93c811b7 ("mmc: renesas-sdhi: Initialize module on RZ/G2L")
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>