can: at91_can: Fix Kconfig dependencies

The at91_can driver is AT91-specific so it should depend on ARCH_AT91
rather than just ARM. Add COMPILE_TEST as an alternative, so that the
driver can still be build-tested elsewhere.
Signed-off-by: NJean Delvare <jdelvare@suse.de>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/Kconfig

@@ -65,7 +65,7 @@ config CAN_LEDS
 
 config CAN_AT91
 	tristate "Atmel AT91 onchip CAN controller"
-	depends on ARM
+	depends on ARCH_AT91 || COMPILE_TEST
 	---help---
 	  This is a driver for the SoC CAN controller in Atmel's AT91SAM9263
 	  and AT91SAM9X5 processors.