drm/vkms: Fix license inconsistent

Fixes license inconsistent related to the VKMS driver and remove the
redundant boilerplate comment.

Fixes: 854502fa ("drm/vkms: Add basic CRTC initialization")

Cc: stable@vger.kernel.org
Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20190206140116.7qvy2lpwbcd7wds6@smtp.gmail.com