omap4: pandaboard: fix up mmc card detect logic

For MMC1 Controller, card detect interrupt source is
twl6030 which is non-gpio. The card detect call back function provides
card present/absent status by reading MMC Control register present
on twl6030. This functionality was introduced in mfd tree on
track to kernel.org

Sync pandaboard to the same and make mmc work.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Adrian Hunter <adrian.hunter@nokia.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>

Acked-by: Kishore Kadiyala <kishore.kadiyala@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Tested-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Madhusudhan Chikkature <madhu.cr@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>