mtd: mtk-quadspi: Remove unneeded pinctrl header

There is no need to include <linux/pinctrl/consumer.h> as no pinctrl
function is used in this driver, so just remove it.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>