Merge branch 'stmmac'

Giuseppe Cavallaro says:

====================
stmmac fixes: EEE and chained mode

These patches are to fix some new problems in the STMMAC driver.

Mandatory changes are for EEE that needs to be disabled if not supported
and for the chain mode that is broken and the kernel panics if this mode
is enabled.

v3: removed a patch from my previous set that touched the stmmac_tx path
    that has not to be applied. Other patches for cleaning-up will be
    sent on top of net-next git repo.

v4: do not surround the defaul buffer selection using Koption and adopt
    a default to 1536bytes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>