Build audio.primary.* with BOARD_VNDK_VERSION

Author: Jiyong Park <jiyong@google.com>
Date:   Thu Jun 29 15:15:58 2017 +0900

    Build audio.primary.* with BOARD_VNDK_VERSION

    pthread.h should be explicitly added.

    Bug: 37342627
    Test: BOARD_VNDK_VERSION=current m -j audio.primary.msm8996
    Change-Id: I908aed7cf9c5aa970d1e4486dcff32d20d44aebd

Author: Rashed Abdel-Tawab <rashed@linux.com>
Date:   Fri Aug 24 09:49:43 2018 -0700

    audio_extn: Add missing pthread.h includes

    Change-Id: I9e2e5a5f2f03cb6ed1a441a94869e653b2ef487d

Change-Id: Iac99d87dcb834e29a0aee8939886ca1e4f3b757f
(cherry picked from commit 2d01112f)