Add low-level initialization for hsmmc controller. Merged into
this patch patch are various improvments and board support by
Grazvydas Ignotas and David Brownell.

Also change wire4 to be wires, as some newer controllers support
8 data lines.

Cc: Pierre Ossman <drzeus-mmc@drzeus.cx>
Signed-off-by: NGrazvydas Ignotas <notasas@gmail.com>
Signed-off-by: NDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: NTony Lindgren <tony@atomide.com>

Add minimal Beagle board support. Based on earlier patches
by Syed Mohammed Khasim with some fixes from linux-omap tree.
Signed-off-by: NSyed Mohammed Khasim <khasim@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>