ARM: imx: remove IRQF_DISABLED

This flag is a NOOP since 2.6.35 and can be removed.

This is an update for 3.11 of a patch already sent for 3.10

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>