staging: zoran: add SPDX GPL-2.0+ license identifier

Add the SPDX GPL-2.0 license identifier to fix checkpatch.pl warning.
Issue found by checkpatch.pl warning:
"WARNING: Missing or malformed SPDX-License-Identifier tag in line 1"
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/media/zoran/videocodec.c

+// SPDX-License-Identifier: GPL-2.0+
 /*
  * VIDEO MOTION CODECs internal API for video devices
  *