Allow Mellanox switch devices to be configured if only I2C bus is set

Mellanox switches (mlxsw) supports I2C systems without PCI, in order to
give the ability to the users to use such functionality, there is need
to update Kconfig.
Signed-off-by: NOhad Oz <ohado@mellanox.com>
Acked-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/Kconfig

@@ -5,7 +5,7 @@
 config NET_VENDOR_MELLANOX
 	bool "Mellanox devices"
 	default y
-	depends on PCI
+	depends on PCI || I2C
 	---help---
 	  If you have a network (Ethernet) card belonging to this class, say Y.