cli: add ability to set audio volume

If the user passes in a third argument to the 'audio' CLI command, use
it as an integer to set the audio level.

BRANCH=storm
BUG=none
TEST=tried generating sounds using the CLI on storm, observed proper
     volume control.

Change-Id: I236d34405f20889275438e5fdc2381d6a7723b07
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/261078
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
1 file changed