drm/amd/display: Remove plane and stream pointers from dc scratch

[Why&How]
Remove several plane and stream pointers from dc for code
refactoring.

Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alvin Lee <alvin.lee2@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Refactor DPP into a component directory

[WHY & HOW]
Move all dpp files to a new dpp directory.

Reviewed-by: Martin Leung <martin.leung@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Revalla Hari Krishna <harikrishna.revalla@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>