drm/amd/display: remove redundant freesync parser for DP

When updating connector under drm_edid infrastructure, many calculations
and validations are already done and become redundant inside AMD driver.
Remove those driver-specific code in favor of the DRM common code.

Signed-off-by: Melissa Wen <mwen@igalia.com>
Co-developed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>