net: sfp: move field definitions along side register index

Just as we do for the A2h enum, arrange the A0h enum to have the
field definitions next to their corresponding register index.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>