Staging: easycap: Upsample microphone audio

Upsampling from 8000 Hz mono to 32000 Hz stereo improves audio/video
synchronization when userspace programs adopt default buffering.  This
is an experimental feature.

Signed-off-by: Mike Thomas <rmthomas@sciolus.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>