net: phy: marvell: constify marvell_hw_stats

The list of stat registers is read-only, so we can declare it as const.

Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/24d7a2f39e0c4c94466e8ad43228fdd798053f3a.1714643285.git.matthias.schiffer@ew.tq-group.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>