net/mlx5: DR, Remove unneeded check from source port builder

Mask validity for ste builders is checked by mlx5dr_ste_build_pre_check
during matcher creation.
It already checks the mask value of source_vport, so removing
this duplicated check.
Also, moving there the check of source_eswitch_owner_vhca_id mask.

Signed-off-by: Alex Vesker <valex@nvidia.com>
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>