alsa_sound: Initial bring up of audio

Initial bring up of basic audio.

Change-Id: I70f527b7d2b5ae268d3e6a1534ca1faf14b6b272
alsa_sound: Enable MSM AudioPolicyManager

-Update AudioPolicyManagerALSA class as per changes
in AudioPolicyManagerBase class.
-Enable the derived AudioPolicyManager.

Change-Id: I2426268c5a3a1b12b03cef2fa75ee661ecc78599
alsa_sound: Bring-up for SSR

- The string passeded to util property_get should be
  of length atleast 90 but it was of length 6 which was thorowing
  compilation error

- All calls to property_get under SSR macro are called with
  string length 128 to remove compilation error

Change-Id: I1c69b9b77278b2491ea3eaab287e874c41acb52e
alsa_sound: fix declaration issue

Signed-off-by: Whitehawkx <xxwhitehawk@gmail.com>