ASoC: msm: add AUXPCM hostless PCM support

There are use cases that require AUXPCM ports to be
enabld without application processor feeding
or capturing audio data. Add routing definition to
enable these type of use cases on AUXPCM ports.

Change-Id: If5d80df55e37f67cbab7f8b8e826a50908b87b0b
Signed-off-by: Patrick Lai <plai@codeaurora.org>