sfc: Allow DRV_GEN events to be used outside of selftests

Formerly, efx_test_eventq_irq() assumed it was the only user of
driver generated events. Allow it to interoperate with other users.

We can create more than 16 channels, so align event codes with
a multiple of 256 not 16.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/sfc/nic.h b/drivers/net/sfc/nic.h
index bbc2c0c..186aab5 100644
--- a/drivers/net/sfc/nic.h
+++ b/drivers/net/sfc/nic.h
@@ -190,8 +190,7 @@
 /* Interrupts and test events */
 extern int efx_nic_init_interrupt(struct efx_nic *efx);
 extern void efx_nic_enable_interrupts(struct efx_nic *efx);
-extern void efx_nic_generate_test_event(struct efx_channel *channel,
-					unsigned int magic);
+extern void efx_nic_generate_test_event(struct efx_channel *channel);
 extern void efx_nic_generate_interrupt(struct efx_nic *efx);
 extern void efx_nic_disable_interrupts(struct efx_nic *efx);
 extern void efx_nic_fini_interrupt(struct efx_nic *efx);