drm/amd/display: Remove Phantom Pipe Check When Calculating K1 and K2

[Why]
K1 and K2 not being setting properly when subVP is active.

[How]
Have phantom pipes use the same programing as the main pipes without
checking the paired stream

Cc: stable@vger.kernel.org
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Austin Zheng <austin.zheng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>