omap_hsmmc: card detect irq bugfix

Work around lockdep issue when card detect IRQ handlers run in
thread context ... it forces IRQF_DISABLED, which prevents all
access to twl4030 card detect signals.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>