media: vsp1: Fix vsp1_regs.h license header

All source files of the vsp1 driver are licensed under the GPLv2+ except
for vsp1_regs.h which is licensed under GPLv2. This is caused by a bad
copy&paste that dates back from the initial version of the driver. Fix
it.

Acked-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Sergei <Shtylyov&lt;sergei.shtylyov@cogentembedded.com>
Acked-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>