Merge branch 'sh_eth-fallback-compat-strings'

Simon Horman says:

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net: sh_eth: add R-Car Gen[12] fallback compatibility strings

Add fallback compatibility strings for R-Car Gen 1 and 2.

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, f.e. Gen 1 and 2. But beyond that its not clear what the relationship
between IP blocks might be. For example, I believe that r8a7790 is older
than r8a7791 but that doesn't imply that the latter is a descendant of the
former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme is being adopted for
drivers for Renesas SoCs.

Changes since v1:
* Correct typos in changelogs
* Consistently use tabs for indentation in bindings document
* Enhance readability of description of bindings usage
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Signed-off-by: David S. Miller <davem@davemloft.net>