Now that "DOC: User command execution" of i915_gem_execbuffer.c is included
in the i915.rst, it is benecifial (for new developers) to read what happens
at the bottom of the driver stack (in terms of bytes written to be read
by the GPU) when processing a user-space batchbuffer.

v5:
  Typo correction of lacking double tick.
Signed-off-by: NKevin Rogovin <kevin.rogovin@intel.com>
Reviewed-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
[Joonas: correcting the patch title]
Signed-off-by: NJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1523001957-6427-4-git-send-email-kevin.rogovin@intel.com