add support for mx2 in i.MX serial driver
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

This patch bases on the one from Daniel Mack. The most important change to
Daniel's patch is to be more generic. This gpio routine supports at least
the i.MX27 and i.MX31 processors.
Signed-off-by: NJuergen Beisert <j.beisert@pengutronix.de>
Acked-by: NDaniel Mack <daniel@caiaq.de>

This patch adds MX3 support for the i.MX internal uart driver.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>