Fix pppd to build with both old and uapi headers.

Bug: 11559337

(cherry picked from commit 5e0738a2d8667ec1ea629649edc4fc5ae453f4a1)

Change-Id: I7a25195e22b3b244e75c9f615c1233e34d92dc4d
Merge tag 'android-4.4.3_r1' of https://android.googlesource.com/platform/external/ppp into HEAD

Android 4.4.3 release 1