Merge branch 'sh_eth-remove-SH_ETH_OFFSET_INVALID-abuses'

Sergei Shtylyov says:

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sh_eth: remove SH_ETH_OFFSET_INVALID abuses

Here's a set of 2 patches against DaveM's 'net-next.git' repo. They get rid of
the abuse of SH_ETH_OFFSET_INVALID for the register existence checks, so that
only its necessary uses would remain...
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Signed-off-by: David S. Miller <davem@davemloft.net>