nfp: ethtool: supplement nfp link modes supported

Add support for the following modes to the nfp driver:

	NFP_MEDIA_10GBASE_LR
	NFP_MEDIA_25GBASE_LR
	NFP_MEDIA_25GBASE_ER

These modes are supported by the hardware and,
support for them was recently added to firmware.

Signed-off-by: Yu Xiao <yu.xiao@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>