ntsc seems to work fine with either algo, some
pal TVs seem pickier.

Fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=30832Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>