net: designware: Drop NULL priv assignment

This is unnecessary, the unset structure member is initialized to
NULL by default, drop the assignment.

Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/drivers/net/designware.c b/drivers/net/designware.c
index 2ab0301..c17b407 100644
--- a/drivers/net/designware.c
+++ b/drivers/net/designware.c
@@ -1041,7 +1041,6 @@
 		.get_mdio	= dw_eth_bb_get_mdio,
 		.set_mdc	= dw_eth_bb_set_mdc,
 		.delay		= dw_eth_bb_delay,
-		.priv		= NULL,
 	}
 };