OMAP: hsmmc: Enable MMC4 and MMC5 on OMAP4 platforms

OMAP4 supports up to 5 MMC controllers, but only 3 of these were
initialized. MMC5 is used by wl12xx chip. So initialize MMC4 and MMC5.

Signed-off-by: Kishore Kadiyala <kishore.kadiyala@ti.com>
Signed-off-by: Panduranga Mallireddy <panduranga_mallireddy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>