Merge branch 'ravb-cleanups'

Niklas Söderlund says:

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ravb: Align Rx descriptor setup and maintenance

When RZ/G2L support was added the Rx code path was split in two, one to
support R-Car and one to support RZ/G2L. One reason for this is that
R-Car uses the extended Rx descriptor format, while RZ/G2L uses the
normal descriptor format.

In many aspects this is not needed as the extended descriptor format is
just a normal descriptor with extra metadata (timestamsp) appended. And
the R-Car SoCs can also use normal descriptors if hardware timestamps
were not desired. This split has led to RZ/G2L gaining support for
split descriptors in the Rx path while R-Car still lacks this.

This series is the first step in trying to merge the R-Car and RZ/G2L Rx
paths so features and bugs corrected in one will benefit the other.

The first patch in the series clarifies that the driver now supports
either normal or extended descriptors, not both at the same time by
grouping them in a union. This is the foundation that later patches will
build on the aligning the two Rx paths.

Patches 2-5 deals with correcting small issues in the Rx frame and
descriptor sizes that either were incorrect at the time they were added
in 2017 (my bad) or concepts built on-top of this initial incorrect
design.

While finally patch 6 merges the R-Car and RZ/G2L for Rx descriptor
setup and maintenance.

When this work has landed I plan to follow up with more work aligning
the rest of the Rx code paths and hopefully bring split descriptor
support to the R-Car SoCs.
====================

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