drm/amdgpu: Fix typo "acccess" and improve the comment style here

There are some spelling mistakes of 'acccess' in comments which
should be instead of 'access'.

And the comment style should be like this:
 /*
  * Text
  * Text
  */

Suggested-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/all/f75fbe30-528e-404f-97e4-854d27d7a401@amd.com/


Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/all/0c768bf6-bc19-43de-a30b-ff5e3ddfd0b3@suse.de/


Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>