Revert "net/mlx5: Expose steering dropped packets counter"

This reverts commit 4fe1b3a5

, which
exposes the steering dropped packets counter via debugfs. The upcoming
series will expose the counter via devlink health reporter instead
of debugfs.

Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>