net/mlx5: Store page counters in a single array

Currently, an independent page counter is used for tracking memory usage
for each function type such as VF, PF and host PF (DPU).

For better code-readibilty, use a single array that stores
the number of allocated memory pages for each function type.

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