pinctrl: imx: Push imx_pinctrl_ops into drivers and staticize

pinctrl: imx: Push imx_pinctrl_ops into drivers and staticize

Move imx_pinctrl_ops into drivers and staticize. This is preparatory
patch for follow up pinctrl drivers which will not use this variant
of imx_pinctrl_ops content. This should not change size, as most of
the deployments compiled in one pinctrl driver anyway. No functional
change.

Signed-off-by: Marek Vasut <marex@denx.de>