drm/amd/display: Set correct EOTF and Gamut flag in VRR info

[Why] FreeSync always use G2.2 EOTF and Native gamut
[How] Set EOTF and Gamut flags accordingly

Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Mike Hsieh <Mike.Hsieh@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>