Merge changes I3fc119b0,I94961f9f,Ic8a86d7a,Iec1e469b,Ic510bf88, ...

* changes:
  Factor BTA_SYS_PLCY_DEF_CLR into its own function
  Factor BTA_SYS_PLCY_DEF_SET into its own function
  Factor BTA_SYS_PLCY_CLR into its own function
  Factor BTA_SYS_PLCY_SET into its own function
  remove p_policy_cb, call into bta_dm directly
  Remove BTA_DM_LP*
  BTA_SYS_EVT_DISABLED_EVT only ever comes in the HW_STOPPING state
  Make BTA_dm_sys_hw_cback just about hw on
  Pull hw off out of BTA_dm_sys_hw_cback
  Pull hardware errors out of BTA_dm_sys_hw_cback
  bta_sys_hw_evt_stack_enabled -> direct call
  bta_sys_hw_evt_disabled -> direct call
  Call BTA_dm_sys_hw_cback directly
  Remove indirection for reporting hardware events
  Don't use event indirection for bta sys hw events