hal: Compilation fixes

 * Properly include path to kernel headers for postproc effects
 * Don't try to build SSR or Listen if QC_PROP_ROOT isn't set

Change-Id: I8f2a874bbbec09cea8eae423a82e6cc59d03f422
hal: Fix compilation with incall music disabled

Change-Id: I977766437664fc87add0469ca8af23a6eb74c57d