Basic driver for ab8500 usb otg transceiver

TODO:
-Regulators support
-Host and OTG testing
-Interface with PRCMU
-Charging support
Signed-off-by: NMian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>