net/mlx5: Expose SF firmware pages counter

Currently, each core device has VF pages counter which stores number of
fw pages used by its VFs and SFs.

The current design led to a hang when performing firmware reset on DPU,
where the DPU PFs stalled in sriov unload flow due to waiting on release
of SFs pages instead of waiting on only VFs pages.

Thus, Add a separate counter for SF firmware pages, which will prevent
the stall scenario described above.

Fixes: 1958fc2f ("net/mlx5: SF, Add auxiliary device driver")
Signed-off-by: Maher Sanalla <msanalla@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>