Commit d952a0eeba37 ("Regenerate defconfig files") disabled the macb
driver in the ZynqMP defconfig, because CONFIG_NET was not enabled in
the defconfig. While not strictly required, you probably want to enable
the macb driver on the ZynqMP.

Enable CONFIG_NET and reenable CONFIG_DRIVER_NET_MACB.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>