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>
diff --git a/drivers/pinctrl/nxp/pinctrl-imxrt.c b/drivers/pinctrl/nxp/pinctrl-imxrt.c
index 23f07f8..fdb3cbe 100644
--- a/drivers/pinctrl/nxp/pinctrl-imxrt.c
+++ b/drivers/pinctrl/nxp/pinctrl-imxrt.c
@@ -27,6 +27,10 @@
 	{ /* sentinel */ }
 };
 
+static const struct pinctrl_ops imx_pinctrl_ops = {
+	.set_state = imx_pinctrl_set_state,
+};
+
 U_BOOT_DRIVER(imxrt_pinctrl) = {
 	.name = "imxrt-pinctrl",
 	.id = UCLASS_PINCTRL,