pinctrl: freescale: imx: Use 'devm_of_iomap()' to avoid a resource leak in case of error in 'imx_pinctrl_probe()'

Use 'devm_of_iomap()' instead 'of_iomap()' to avoid a resource leak in
case of error.

Update the error handling code accordingly.

Fixes: 26d8cde5 ("pinctrl: freescale: imx: add shared input select reg support")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200602200626.677981-1-christophe.jaillet@wanadoo.frSigned-off-by: Linus Walleij <linus.walleij@linaro.org>