libweave: Use atomic gyp file

libweave is going to switch to make files so libweave.gypi is going
away.
Also removed targets which are not useful anymore on ChromeOS.

BUG=None
TEST=None

Change-Id: Ic72fa508b50438fc5fa38496c41b96f5876d83f4
Reviewed-on: https://chromium-review.googlesource.com/321983
Commit-Ready: Vitaly Buka <vitalybuka@chromium.org>
Tested-by: Vitaly Buka <vitalybuka@chromium.org>
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
1 file changed