net/mlx5e: Move an_disable_cap bit to a new position

Previous an_disable_cap position bit31 is deprecated to be use in driver
with newer firmware.  New firmware will advertise the same capability
in bit29.

Old capability didn't allow setting more than one protocol for a
specific speed when autoneg is off, while newer firmware will allow
this and it is indicated in the new capability location.

Signed-off-by: Bodong Wang <bodong@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>