Remove unused defines and methods in internal_defines.h
Remove unused defines and methods in internal_defines.h

Bug: none
Change-Id: Ia73dda32373fb367b6163f1157392c9d8077e4fc
Reviewed-on: https://webrtc-review.googlesource.com/c/116281
Reviewed-by: Rasmus Brandt <9545de3a34b925a736ae2b5ee593f3033f743a28@webrtc.org>
Commit-Queue: Åsa Persson <5ff7466874d1fe71d5fe7d79a8a23f5ef50662da@webrtc.org>
Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#26421}
ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,TimothyGu/libilbc,ShiftMediaProject/libilbc,ShiftMediaProject/libilbc