Merge branch 'net-mvmdio-performance-related-improvements'

Tobias Waldekranz says:

====================
net: mvmdio: Performance related improvements

Observations of the XMDIO bus on a CN9130-based system during a
firmware download showed a very low bus utilization, which stemmed
from the 150us (10x the average access time) sleep which would take
place when the first poll did not succeed.

With this series in place, bus throughput increases by about 10x,
multiplied by whatever gain you are able to extract from running the
MDC at a higher frequency (hardware dependent).
====================

Link: https://lore.kernel.org/r/20231204100811.2708884-1-tobias@waldekranz.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>