linux-yocto: enable an AC-97 audio controller driver

This kernel bbappend for 3.4 is modified to enable AC-97 audio
controller driver as built-in module for qemux86 machine and
is needed to sound out on VirtualBox.

[GF-8026] Audio does not work in emulator due to lack of AC97
support in linux-yocto kernel.

Open-webOS-DCO-1.0-Signed-off-by: Minjung Kim <mjane.kim@lge.com>
Open-webOS-DCO-1.0-Signed-off-by: Steve Lemke <steve.lemke@lge.com>

Change-Id: Ia7efee1a9c188c7bb207451b0b27e6134c461e71
Reviewed-on: https://g2g.palm.com/2724
Reviewed-by: Steve Lemke <steve.lemke@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>
Tested-by: Susan Montooth <susan.montooth@lge.com>