drm: fix drm_gem_vram_helper.h kernel-doc

Remove excess funcs kernel-doc.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/02000be3455de639f32bde88f632ae8744142083.1709749576.git.jani.nikula@intel.com

include/drm/drm_gem_vram_helper.h

@@ -170,7 +170,6 @@ void drm_gem_vram_simple_display_pipe_cleanup_fb(
  * @vram_base:	Base address of the managed video memory
  * @vram_size:	Size of the managed video memory in bytes
  * @bdev:	The TTM BO device.
- * @funcs:	TTM BO functions
  *
  * The fields &struct drm_vram_mm.vram_base and
  * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are