staging: solo6x10: add select SND_PCM to fix build error

This patch fixes a build error when SND_PCM is not set
by adding a select statment.

Signed-off-by: Peter Foley <pefoley2@verizon.net>
Acked-By: Ben Collins <bcollins@bluecherry.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>