Add USB OTG, peripheral and host devices. This patch also adds
usb_phy_clk which is required for resetting the PHY. VBUS power up
and shutdown routines depends on PMIC module. As PMIC driver is
unavailable, configure USB in peripheral only mode.
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org> Signed-off-by: David Brown <davidb@codeaurora.org>