can: Kconfig: convert 'depends on CAN_DEV' into 'if CAN_DEV...endif' block

This patch adds an 'if CAN_DEV...endif' Block around the CAN driver
symbols in drivers/net/can/Kconfig. So the 'depends on CAN' dependencies
can be removed.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/usb/Kconfig b/drivers/net/can/usb/Kconfig
index a4e4bee..acba33d 100644
--- a/drivers/net/can/usb/Kconfig
+++ b/drivers/net/can/usb/Kconfig
@@ -1,5 +1,5 @@
 menu "CAN USB interfaces"
-	depends on USB && CAN_DEV
+	depends on USB
 
 config CAN_EMS_USB
 	tristate "EMS CPC-USB/ARM7 CAN/USB interface"