USB: Fix FSL USB driver on non Open Firmware systems

Commit 126512e3f274802ca65ebeca8660237f0361ad48 added support for FSL's USB
controller on powerpc. In this commit the Open Firmware code was selected
and compiled unconditionally.

This breaks on ARM systems from FSL which use the same driver (.i.e. the i.MX
series), because ARM don't have OF support (yet). This patch fixes the problem
by only selecting the OF code on systems with Open Firmware support.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Compile-Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -158,7 +158,7 @@ config USB_GADGET_FSL_USB2
 	boolean "Freescale Highspeed USB DR Peripheral Controller"
 	depends on FSL_SOC || ARCH_MXC
 	select USB_GADGET_DUALSPEED
-	select USB_FSL_MPH_DR_OF
+	select USB_FSL_MPH_DR_OF if OF
 	help
 	   Some of Freescale PowerPC processors have a High Speed
 	   Dual-Role(DR) USB controller, which supports device mode.

drivers/usb/host/Kconfig

@@ -122,7 +122,7 @@ config USB_EHCI_FSL
 	bool "Support for Freescale on-chip EHCI USB controller"
 	depends on USB_EHCI_HCD && FSL_SOC
 	select USB_EHCI_ROOT_HUB_TT
-	select USB_FSL_MPH_DR_OF
+	select USB_FSL_MPH_DR_OF if OF
 	---help---
 	  Variation of ARC USB block used in some Freescale chips.