asix: AX88172A driver depends on phylib

Since commit 16626b0c the asix
driver depends on the phylib. Select phylib when the asix driver is
selected.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: kernel-janitors@vger.kernel.org
Signed-off-by: NChristian Riesch <christian.riesch@omicron.at>
Tested-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/usb/Kconfig

@@ -134,6 +134,7 @@ config USB_NET_AX8817X
 	tristate "ASIX AX88xxx Based USB 2.0 Ethernet Adapters"
 	depends on USB_USBNET
 	select CRC32
+	select PHYLIB
 	default y
 	help
 	  This option adds support for ASIX AX88xxx based USB 2.0