ARM: mach-shmobile: add GPIO definitions for switching between LCDC0 and LCDC1

With these defines now it is possible to use
gpio_request(GPIO_FN_LCDC1_SELECT, NULL) or ...LCDC0... respectively to
switch between the two LCDC instances.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>