ALSA: [hdspm] Move static mapping arrays to .c

As requested by Takashi and Jaroslav, these arrays should not be in the
header file.

Signed-off-by: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Signed-off-by: Takashi Iwai <tiwai@suse.de>