ASoC: msm: change default Dolby endpoint to EXT speakers

Android endpoint device is mapped to Dolby endpoint device and sent
to DAP post proc module in dsp. Dolby suggests the default device
should be external speakers when we can't find the mapping like in
case of combo devices in use.

Change-Id: Id6ff82f9430538a9e1f75a09a2be7e51cce9977d
Signed-off-by: Jitendra Singh Naruka <jnaruk@codeaurora.org>