net: mv643xx_eth: process retval from of_get_mac_address

Obtaining a MAC address may be deferred in cases when the MAC is stored
in an NVMEM block, for example, and it may not be ready upon the first
retrieval attempt and return EPROBE_DEFER.

It is also possible that a port that does not rely on NVMEM has been
already created when getting the defer request. Thus, also the resources
allocated previously must be freed when doing a roll-back.

Fixes: 76723bca

 ("net: mv643xx_eth: add DT parsing support")
Signed-off-by: Mauri Sandberg <maukka@ext.kapsi.fi>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220223142337.41757-1-maukka@ext.kapsi.fi


Signed-off-by: Jakub Kicinski <kuba@kernel.org>