samsung: usb: phy: Support for DWC3 PHY

New files, namely samsung_usb_phy.c and samsung-usb-phy-uboot.h have
been added to u-boot to provide proper PHY handling at Exynos5 SoCs.

This code is used thereafter in the board_usb_init() call.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index e455a52..02bb216 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -6,3 +6,4 @@
 
 obj-$(CONFIG_USB_DWC3_OMAP)		+= dwc3-omap.o
 obj-$(CONFIG_USB_DWC3_PHY_OMAP)		+= ti_usb_phy.o
+obj-$(CONFIG_USB_DWC3_PHY_SAMSUNG)	+= samsung_usb_phy.o