USB: at91: Add USB EHCI driver for at91sam9g45 series

Add host USB High speed driver for at91sam9g45 series.
The host driver is an EHCI with its companion OHCI. EHCI is
handled by the new ehci-atmel.c whereas the OHCI is always
handled by ohci-at91.c.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>

drivers/usb/Kconfig

@@ -60,6 +60,7 @@ config USB_ARCH_HAS_EHCI
 	default y if SOC_AU1200
 	default y if ARCH_IXP4XX
 	default y if ARCH_W90X900
+	default y if ARCH_AT91SAM9G45
 	default PCI
 
 # ARM SA1111 chips have a non-PCI based "OHCI-compatible" USB host interface.