shill: Update gyp files to pick up wimax_manager code from platform2. BUG=chromium:370264 CQ-DEPEND=CL:205474 CQ-DEPEND=CL:205484 TEST=`USE='gdmwimax wimax' FEATURES=test emerge-$BOARD platform2` Change-Id: I8d7aed33decd6552d57dbddd7bf09f4fc70f6d94 Reviewed-on: https://chromium-review.googlesource.com/205483 Reviewed-by: Mike Frysinger <vapier@chromium.org> Commit-Queue: Ben Chan <benchan@chromium.org> Tested-by: Ben Chan <benchan@chromium.org>