ARM: shmobile: ap4evb: Register pinctrl mapping for TSC2007

Replace the GPIO-based TSC2007 pinmux configuration by a pinctrl
mapping.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>