staging: vc04_services: bcm2835-audio: add SPDX identifiers

staging: vc04_services: bcm2835-audio: add SPDX identifiers

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Fix up the bcm2835-audio driver to have a proper SPDX identifier, based
on the license text in the file itself.  The SPDX identifier is a
legally binding shorthand, which can be used instead of the full boiler
plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: <bcm-kernel-feedback-list@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>