pinctrl: zynq: Initialize early

Supplying pinmux configuration for e.g. gpio pins leads to deferred
probes because the pinctrl device is probed much later than gpio.
Move the init call to a much earlier stage so it probes before the
devices that may need it.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
Tested-by: Sören Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>