phy: Add a driver for dm816x USB PHY

Add a minimal driver for dm816x USB. This makes USB work on dm816x
without any other changes needed as it can use the existing musb_dsps
glue layer for the USB controller.

Note that this phy is different from dm814x and am335x.

Cc: Bin Liu <binmlist@gmail.com>
Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Matthijs van Duin <matthijsvanduin@gmail.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 2962de2..885c39c 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -35,6 +35,13 @@
 	depends on OF
 	select GENERIC_PHY
 
+config PHY_DM816X_USB
+	tristate "TI dm816x USB PHY driver"
+	depends on ARCH_OMAP2PLUS
+	select GENERIC_PHY
+	help
+	  Enable this for dm816x USB to work.
+
 config PHY_EXYNOS_MIPI_VIDEO
 	tristate "S5P/EXYNOS SoC series MIPI CSI-2/DSI PHY driver"
 	depends on HAS_IOMEM