Merge branch 'gve-ring-size-changes'

Harshitha Ramamurthy says:

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gve: enable ring size changes

This series enables support to change ring size via ethtool
in gve.

The first three patches deal with some clean up, setting
default values for the ring sizes and related fields. The
last two patches enable ring size changes.
====================

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