Revert "net/mlx5e: Expose PCIe statistics to ethtool"

This reverts commit 9c726239.
PCIe counters were introduced in a new firmware version, as a result users
with old firmware encountered a syndrome every 200ms due to update stats
work. This feature will be re-introduced later with appropriate capabilities
infrastructure.

Fixes: 9c726239 ("net/mlx5e: Expose PCIe statistics to ethtool")
Signed-off-by: Gal Pressman <galp@mellanox.com>
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>