Classify DCE6 resource and sequencer as they are for other DCE versions
Put dce60_resource.c and .h under amd/display/dc/resource/dce60
Put and rename dce60_hw_sequencer.c and .h under amd/display/dc/hwss/dce60
v2: fix build when CONFIG_DRM_AMD_DC_SI=n (Alex)
Signed-off-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
