rockchip: rk3036: Bind GPIO banks

Call dm_scan_fdt_node() in rk3036 pinctrl uclass binding.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>