drm/msm/registers: Remove license/etc from generated headers

drm/msm/registers: Remove license/etc from generated headers

Since these generated files are no longer checked in, either in mesa or
in the linux kernel, simplify things by dropping the verbose generated
comment.

These were semi-nerf'd on the kernel side, in the name of build
reproducibility, by commit ba64c6737f86 ("drivers: gpu: drm: msm:
registers: improve reproducibility"), but in a way that was semi-
kernel specific.  We can just reduce the divergence between kernel
and mesa by just dropping all of this.

Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/673551/