This adds a routine to initialize the GMAC at the port level when using
a port. This wasn't done until this commit, and the mvpp2 driver was
relying on the bootloader/firmware initialization. This doesn't mean
everything is configured in the mvpp2 driver now, but it helps reducing
the gap.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Tested-by: Marcin Wojtas <mw@semihalf.com> Signed-off-by: David S. Miller <davem@davemloft.net>