sh: Use sh7723 GPIO on AP325RXA board

This patch enables the GPIO code on AP325RXA and converts the code from
register based pinmux configuration to GPIO based pin by pin setup.
While at it 2 LEDs and one switch are added and exported to user space.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>