ALSA: core: Add SPDX license id to files

ALSA: core: Add SPDX license id to files

Add an SPDX id of LGPL-2.0+ to files in the
sound core sub-system that are missing ids.  Remove
boilerplate text.

These files were originally submitted in a big commit
for the ALSA sound system for kernel version 2.5.4,
by Jaroslav Kysela, in Feb 2002.

Signed-off-by: Tim Bird <tim.bird@sony.com>
Link: https://patch.msgid.link/20260212183103.3720788-1-tim.bird@sony.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>