usb: move phy driver from mach-tegra to drivers/usb

As part of this patch:
	1. Moved existing tegra phy driver to drivers/USB directory.
	2. Added standard USB phy driver APIs to tegra phy driver.

Signed-off-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index cf38f08..bb948fb 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -6,3 +6,4 @@
 
 obj-$(CONFIG_USB_ISP1301)		+= isp1301.o
 obj-$(CONFIG_MV_U3D_PHY)		+= mv_u3d_phy.o
+obj-$(CONFIG_USB_EHCI_TEGRA)	+= tegra_usb_phy.o