USB: fsl_usb2_udc: fix broken Kconfig

The patch fixes broken Kconfig caused by the name change of MPC834x option.
It also makes fsl_usb2_udc selectable on new platforms like MPC837x.
Signed-off-by: Li Yang <leoli@freescale.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/Kconfig

@@ -131,7 +131,7 @@ config USB_ATMEL_USBA
 
 config USB_GADGET_FSL_USB2
 	boolean "Freescale Highspeed USB DR Peripheral Controller"
-	depends on MPC834x || PPC_MPC831x
+	depends on FSL_SOC
 	select USB_GADGET_DUALSPEED
 	help
 	   Some of Freescale PowerPC processors have a High Speed