drm/amd/display: fix issue related to infopacket was not transmitted

Check in code was incorrect, and infopacket is only transmitted after update
function is called multiple times.
Purpose of the function was to check if infopackets are being enabled, and
then enable global control. Fix the code to do this.

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>