OMAP2420 platform consists of mmc block as in omap1 and not the
hsmmc block as present in omap2430, omap3, omap4 platforms.
Removing all base address macro defines except keeping one for OMAP2420 and
adapting only hsmmc device registration and driver to hwmod framework.

Changes involves:
1) Remove controller reset in devices.c which is taken care of
   by hwmod framework.
2) Using omap-device layer to register device and utilizing data from
   hwmod data file for base address, dma channel number, Irq_number,
   device attribute.
3) Update the driver to use dev_attr to find whether controller
   supports dual volt cards
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com>
Reviewed-by: Balaji T K <balajitk@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
CC: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>