sh: Use sh7722 GPIO on Migo-R board

This patch enables the GPIO code on Migo-R and converts the code from
register based pinmux configuration to GPIO based pin by pin setup.
Fix whitespace damage while at it and add 2 LEDs and export them to
user space.

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