Merge changes from topic "pppolac"

* changes:
  mtpd: Use L2TP implementation from mainline kernel
  mtpd: l2tp: Fix endianness issues in log prints
  mtpd: Remove obsolete way of passing args to pppd
tree: 4a1fefc53ec2b7d3daf7db87a589b1ddf1a0140b
  1. Android.bp
  2. l2tp.c
  3. MODULE_LICENSE_APACHE2
  4. mtpd.c
  5. mtpd.h
  6. mtpd.rc
  7. NOTICE
  8. pptp.c