drm/i915/gvt: Remove incorrect kerneldoc marking

Just a normal comment, not a kerneldoc function description.

drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'vgpu' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'offset' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'p_data' not described in 'bxt_ppat_low_write'
drivers/gpu/drm/i915/gvt/handlers.c:1666: warning: Function parameter or member 'bytes' not described in 'bxt_ppat_low_write'

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103204307.15723-1-chris@chris-wilson.co.uk