omap4: mmc driver support on OMAP4

Add basic support for all 5 MMC controllers on OMAP4.

This patch doesn't include mmc-regulator support

Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com>
Cc: Jarkko Lavinen <jarkko.lavinen@nokia.com>
Acked-by: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Cc: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>