net: sparx5: fix wrong config being used when reconfiguring PCS

[ Upstream commit 33623113 ]

The wrong port config is being used if the PCS is reconfigured. Fix this
by correctly using the new config instead of the old one.

Fixes: 946e7fd5

 ("net: sparx5: add port module support")
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://lore.kernel.org/r/20240409-link-mode-reconfiguration-fix-v2-1-db6a507f3627@microchip.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>