ARM: mxs: Remove unneeded #include <linux/pinctrl/consumer.h>

Commit 7705b5ed ("ARM: mxs: remove obsolete startup code for
TX28") removed the last user of the pinctrl consumer API.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>