Merge branch 'bgmac'

bgmac: add initial support for core rev 4 on ARM BCM47xx

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This adds support for core rev 4 and ARM BCM47XX.
With an other fix to the platform code I am now getting over 200 MBit/s
with this Ethernet driver, the DMA problems are solved are unrelated
to bgmac.

v3:
   - moved flags calculation for bcma_core_enable() into if block
   - remove hard coding of phy address to BGMAC_PHY_NOREGS

v2: add changed suggested by Rafał
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Signed-off-by: David S. Miller <davem@davemloft.net>