Fixes [BUGID #488 #734]

Enable audio for qemux86/qemux86-64 via the following kernel
configuration options.

CONFIG_SOUND_OSS_CORE=y
CONFIG_SOUND_OSS_CORE_PRECLAIM=y
CONFIG_SND_RAWMIDI=m
CONFIG_SND_SEQUENCER=y
CONFIG_SND_OSSEMUL=y
CONFIG_SND_MIXER_OSS=y
CONFIG_SND_PCM_OSS=y
CONFIG_SND_PCM_OSS_PLUGINS=y
CONFIG_SND_SEQUENCER_OSS=y
CONFIG_SND_RAWMIDI_SEQ=m
CONFIG_SND_AC97_CODEC=m
CONFIG_SND_ENS1370=m
CONFIG_SND_INTEL8X0=m
CONFIG_AC97_BUS=m

The mechanism to trigger these options is in the form of an
optional kernel feature that is only appended for qemux86
and qemux86-64, but is contained within the kernel tree.

This allows several things:

- the options to be available/shared for all boards
- the options to be in tree
- to not add the options to every board, which unecessarily
bloats the default configuration.

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>