phy: sparx5-serdes: configure optimal quiet mode for serdes lanes

All the serdes lanes of the sparx5 will transition between normal mode
and quiet mode, depending on activity. Make sure that the quiet mode is
configured optimally for all lanes initially. Although not much, this
will save a small amount of power.

Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Link: https://lore.kernel.org/r/20230417180335.2787494-3-daniel.machon@microchip.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>