bnx2x: convert EEE handling to use linkmode bitmaps

Convert EEE handling to use linkmode bitmaps. This prepares for
removing the legacy bitmaps from struct ethtool_keee.
No functional change intended.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/948562fb-c5d8-4912-8b88-bec56238732a@gmail.com


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