pinctrl: imx: Rename imx_pinctrl_remove() to imx_pinctrl_remove_mmio()

The current implementation of imx_pinctrl_remove() is specific
to the MMIO accessor implementation, rename the function to
imx_pinctrl_remove_mmio() to make this obvious. 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 a8db355..84ca93c 100644
--- a/drivers/pinctrl/nxp/pinctrl-imxrt.c
+++ b/drivers/pinctrl/nxp/pinctrl-imxrt.c
@@ -28,7 +28,7 @@
 	.id = UCLASS_PINCTRL,
 	.of_match = of_match_ptr(imxrt_pinctrl_match),
 	.probe = imx_pinctrl_probe_mmio,
-	.remove = imx_pinctrl_remove,
+	.remove = imx_pinctrl_remove_mmio,
 	.priv_auto	= sizeof(struct imx_pinctrl_priv),
 	.ops = &imxrt_pinctrl_ops,
 	.flags = DM_FLAG_PRE_RELOC,