net: pcs: lynx: no need to read LPA in lynx_pcs_get_state_2500basex()

Nothing useful is done with the LPA variable in lynx_pcs_get_state_2500basex(),
we can just remove the read.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20240513115345.2452799-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>