pinctrl: exit pinconfig_post_bind if there are no subnodes

This fixes RK3288 SPL hanging or hitting this assert:
drivers/core/ofnode.c:183: ofnode_first_subnode: Assertion `ofnode_valid(node)' failed.

Signed-off-by: Urja Rannikko <urjaman@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
1 file changed