usb: s3c-otg: Split out PHY control

Split the Samsung specific PHY control into a separate file
and compile this into the S3C OTG driver only if used on a
Samsung system.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Acked-by: Pavel Machek <pavel@denx.de>
Cc: Stefan Roese <sr@denx.de>
Reviewed-by: Lukasz Majewski <l.majewski@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
diff --git a/include/configs/exynos4-common.h b/include/configs/exynos4-common.h
index 89ba14e..41631c7 100644
--- a/include/configs/exynos4-common.h
+++ b/include/configs/exynos4-common.h
@@ -59,6 +59,7 @@
 
 #define CONFIG_USB_GADGET
 #define CONFIG_USB_GADGET_S3C_UDC_OTG
+#define CONFIG_USB_GADGET_S3C_UDC_OTG_PHY
 #define CONFIG_USB_GADGET_DUALSPEED
 #define CONFIG_USB_GADGET_VBUS_DRAW	2