qed, qede, qedf: convert link mode from u32 to ETHTOOL_LINK_MODE

Currently qed driver already ran out of 32 bits to store link modes,
and this doesn't allow to add and support more speeds.
Convert custom link mode to generic Ethtool bitmap and definitions
(convenient Phylink shorthands are used for elegance and readability).
This allowed us to drop all conversions/mappings between the driver
and Ethtool.

This involves changes in qede and qedf as well, as they used definitions
from shared "qed_if.h".

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexander Lobakin <alobakin@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>