nfp: ethtool: support TX/RX pause frame on/off

Add support for ethtool -A tx on/off and rx on/off.

Signed-off-by: Yu Xiao <yu.xiao@corigine.com>
Signed-off-by: Louis Peens <louis.peens@corigine.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231127055116.6668-1-louis.peens@corigine.com


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