drm/amdgpu: change the comment from handle to ip_block

drm/amdgpu: change the comment from handle to ip_block

htmldoc generation depend upon the input arguments etc
to generate the document. After update of handle to
ip_block then update needs in comments too to fix the
warnings.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202410021904.YyGjlpk9-lkp@intel.com
Signed-off-by: Sunil Khatri <sunil.khatri@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>