sfc: Add GFP flags to efx_nic_alloc_buffer() and make most callers allow blocking

Most call sites for efx_nic_alloc_buffer() are part of the probe or
reconfiguration paths and can allocate with GFP_KERNEL.  A few others
should use GFP_NOIO (I think).  Only one is in atomic context and
must use the current GFP_ATOMIC.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index d96bfc4..56a8b88 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -875,7 +875,7 @@
 	if (!efx->ptp_data)
 		return -ENOMEM;
 
-	rc = efx_nic_alloc_buffer(efx, &ptp->start, sizeof(int));
+	rc = efx_nic_alloc_buffer(efx, &ptp->start, sizeof(int), GFP_KERNEL);
 	if (rc != 0)
 		goto fail1;