USB: drivers/usb/Makefile: conditionally descend to 'early'

Don't descend to the EARLY_PRINTK_DBGP directory
unless it is actually used.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/Makefile

@@ -41,7 +41,7 @@ obj-$(CONFIG_USB_MICROTEK)	+= image/
 obj-$(CONFIG_USB_SERIAL)	+= serial/
 
 obj-$(CONFIG_USB)		+= misc/
-obj-y				+= early/
+obj-$(CONFIG_EARLY_PRINTK_DBGP)	+= early/
 
 obj-$(CONFIG_USB_ATM)		+= atm/
 obj-$(CONFIG_USB_SPEEDTOUCH)	+= atm/