drm/amd/display: Adjust kdoc for 'optc35_set_odm_combine'
Fixes the following W=1 kernel build warning:
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn35/dcn35_optc.c:46: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
* Enable CRTC