pinctrl: disable and free setting in select_state in case of error

If enabling a pin fails in pinctrl_select_state_locked(), all the
previous enabled pins have to be disabled to get back to the previous
state.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>