mlx5: Rename the vport number enums for host PF and VF

mlx5: Rename the vport number enums for host PF and VF

Rename the vport number enums MLX5_VPORT_PF to MLX5_VPORT_HOST_PF and
MLX5_VPORT_FIRST_VF to MLX5_VPORT_FIRST_HOST_VF to indicate that these
vport indices represent the host PF and its VFs. This prepares the code
for upcoming support of an additional PF type.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260428053851.220089-2-tariqt@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>