drm/amd/display: LFC not working on 2.0x range monitors (v2)
[Why]
Nominal pixel clock and EDID information differ in precision so although
monitor reports maximum refresh is 2x minimum, LFC was not being
enabled.
[How]
Use minimum refresh rate as nominal/2 when EDID dictates that min
refresh = max refresh/2.
v2: squash in 64 bit divide fix
Signed-off-by: Aric Cyr <aric.cyr@amd.com> Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>