Add platform init code for EHCI driver.

Various fixes to the original patch by Ajay Kumar Gupta <ajay.gupta@ti.com>
and Anand Gadiyar <gadiyar@ti.com>.

Overo support added by Olof Johansson <olof@lixom.net>
Beagle support added by Koen Kooi <koen@beagleboard.org>
CM-T32 support added by Mike Rapoport <mike@compulab.co.il>
Signed-off-by: NSigned-off-by: Olof Johansson <olof@lixom.net>
Acked-by: NSteve Sakoman <steve@sakoman.com>
Signed-off-by: NKoen Kooi <koen@beagleboard.org>
Signed-off-by: NMike Rapoport <mike@compulab.co.il>
Signed-off-by: NAjay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: NAnand Gadiyar <gadiyar@ti.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>