bnxt: convert EEE handling to use linkmode bitmaps

bnxt: 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. When replacing _bnxt_fw_to_ethtool_adv_spds() with
_bnxt_fw_to_linkmode(), remove the fw_pause argument because it's
always passed as 0.

Note:
There's a discussion on whether the underlying implementation is correct,
but it's independent of this mechanical conversion w/o functional change.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Michael Chan <michael.chan@broadcom.com>
Link: https://lore.kernel.org/r/9123bf18-a0d0-404e-a7c4-d6c466b4c5e8@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>