drm/amd/display: Replace ternary operator with min() in 'dm_helpers_parse_edid_caps'

Fixes the following coccicheck:

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c:120:41-42: WARNING opportunity for min()

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>