Convert CONFIG_USB_XHCI_OMAP to Kconfig

This converts the following to Kconfig:
   CONFIG_USB_XHCI_OMAP

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/am43xx_evm_usbhost_boot_defconfig b/configs/am43xx_evm_usbhost_boot_defconfig
index 8ee16a2..9efeccc 100644
--- a/configs/am43xx_evm_usbhost_boot_defconfig
+++ b/configs/am43xx_evm_usbhost_boot_defconfig
@@ -79,6 +79,7 @@
 CONFIG_USB=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_XHCI_DWC3=y
+CONFIG_USB_XHCI_OMAP=y
 CONFIG_USB_DWC3=y
 CONFIG_USB_DWC3_OMAP=y
 CONFIG_USB_DWC3_GENERIC=y