pinctrl: freescale: imx: Fix an error handling path in 'imx_pinctrl_probe()'

pinctrl: freescale: imx: Fix an error handling path in 'imx_pinctrl_probe()'

'pinctrl_unregister()' should not be called to undo
'devm_pinctrl_register_and_init()', it is already handled by the framework.

This simplifies the error handling paths of the probe function.
The 'imx_free_resources()' can be removed as well.

Fixes: 959101fa1337 ("pinctrl: imx: use radix trees for groups and functions")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Link: https://lore.kernel.org/r/20200530204955.588962-1-christophe.jaillet@wanadoo.fr
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>