usb: dra7xx: Add support for dra7xx xhci USB host

Add the support for the dra7xx xhci usb host.
dra7xx does not contain an EHCI controller so the headers
can be removed from the board file.

The xHCI host on dra7xx is connected to a usb2 phy so need to
add support to enable those clocks.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
diff --git a/include/configs/dra7xx_evm.h b/include/configs/dra7xx_evm.h
index 3a4c06b..a9f39f2 100644
--- a/include/configs/dra7xx_evm.h
+++ b/include/configs/dra7xx_evm.h
@@ -67,4 +67,15 @@
 #define CONFIG_SPL_SPI_CS              0
 #define CONFIG_SYS_SPI_U_BOOT_OFFS     0x20000
 
+/* USB xHCI HOST */
+#define CONFIG_CMD_USB
+#define CONFIG_USB_HOST
+#define CONFIG_USB_XHCI
+#define CONFIG_USB_XHCI_OMAP
+#define CONFIG_USB_STORAGE
+#define CONFIG_SYS_USB_XHCI_MAX_ROOT_PORTS 2
+
+#define CONFIG_OMAP_USB_PHY
+#define CONFIG_OMAP_USB2PHY2_HOST
+
 #endif /* __CONFIG_DRA7XX_EVM_H */