Merge branch 'cpsw-delete-rx_descs'

Ivan Khoronzhuk says:

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net: ethernet: ti: cpsw: delete rx_descs property

There is no reason in rx_descs property because davinici_cpdma
driver splits pool of descriptors equally between tx and rx channels.
So, this patch series makes driver to use available number of
descriptors for rx channels.
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Signed-off-by: David S. Miller <davem@davemloft.net>