phy: exynos-usb2: add vbus regulator support

Exynos USB2 PHY has separate power supply, which is usually provided by
VBUS regulator. This patch adds support for it. VBUS regulator is
optional, to keep compatibility with boards, which have VBUS provided
from some always-on power source.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
diff --git a/drivers/phy/phy-samsung-usb2.h b/drivers/phy/phy-samsung-usb2.h
index 44bead9..6563e7c 100644
--- a/drivers/phy/phy-samsung-usb2.h
+++ b/drivers/phy/phy-samsung-usb2.h
@@ -17,6 +17,7 @@
 #include <linux/device.h>
 #include <linux/regmap.h>
 #include <linux/spinlock.h>
+#include <linux/regulator/consumer.h>
 
 #define KHZ 1000
 #define MHZ (KHZ * KHZ)
@@ -37,6 +38,7 @@
 	const struct samsung_usb2_phy_config *cfg;
 	struct clk *clk;
 	struct clk *ref_clk;
+	struct regulator *vbus;
 	unsigned long ref_rate;
 	u32 ref_reg_val;
 	struct device *dev;