media: dvb-frontend/mxl5xx: Remove repeated verbose license text

remove it because SPDX-License-Identifier is already used

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

media: dvb-frontends/mxl5xx: add SPDX license identifier

As it is clear that the driver is licensed under the terms of GPLv2-only
by now, add a matching SPDX license identifier to all driver files.

Cc: Ralph Metzler <rjkm@metzlerbros.de>
Cc: Manfred Voelkel <mvoelkel@DigitalDevices.de>
Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

media: dvb-frontends: MaxLinear MxL5xx DVB-S/S2 tuner-demodulator driver

This adds the frontend driver for the MaxLinear MxL5xx family of tuner-
demodulators, as used on Digital Devices MaxS4/8 four/eight-tuner cards.

The driver was picked from the dddvb vendor driver package and - judging
solely from the diff - has undergone a 100% rework:

- Silly #define's used to pass multiple values to functions were
expanded. This resulted in macro/register names not being usable
anymore for such occurences, but makes the code WAY more read-,
understand- and maintainable.
- CamelCase was changed to kernel_case
- All typedef were removed
- Overall code style was fixed, besides >80char lines in _defs.h and
_regs.h, checkpatch is happy.
- Also, signal stat acquisition was made to comply with the DVB API
ways to do these things.

Permission to reuse and mainline the driver code was formally granted by
Ralph Metzler <rjkm@metzlerbros.de>.

Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>