pinctrl: do not set_state for device without valid ofnode

Not all the udevice have a available DT node, eg. rksdmmc@ff500000.blk
which add by mmc_bind(), these device do not have/need set pinctrl
state.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>