drm/amd/display: Limit max DSC target bpp for specific monitors

drm/amd/display: Limit max DSC target bpp for specific monitors

commit 55eea8ef98641f6e1e1c202bd3a49a57c1dd4059 upstream.

[Why]
Some monitors exhibit corruption at 16bpp DSC.

[How]
- Add helpers for patching edid caps.
- Use it for limiting DSC target bitrate to 15bpp for known monitors

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Roman Li <Roman.Li@amd.com>
Cc: stable@vger.kernel.org
Tested-by: Daniel Wheeler <Daniel.Wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>