treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[media] pci: Add tw5864 driver

Support for boards based on Techwell TW5864 chip which provides
multichannel video & audio grabbing and encoding (H.264, MJPEG,
ADPCM G.726).

This submission implements only H.264 encoding of all channels at D1
resolution.

Thanks to Mark Thompson <sw@jkqxz.net> for help, and for contribution of
H.264 startcode emulation prevention code.

Signed-off-by: Andrey Utkin <andrey.utkin@corp.bluecherry.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>