common-mk: enable LFS by default

We did this for all common.mk projects, but it was missed for gyp ones.
This shouldn't impact any 64bit systems, just 32bit.

BUG=chromium:464024
TEST=precq passes on 32bit systems

Change-Id: I3a3a52e7cfff1fa2e8737391c211667a881ca1e4
Reviewed-on: https://chromium-review.googlesource.com/262900
Reviewed-by: Daniel Ehrenberg <dehrenberg@chromium.org>
Trybot-Ready: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
diff --git a/update_engine.gyp b/update_engine.gyp
index 6cbf8a7..86981d0 100644
--- a/update_engine.gyp
+++ b/update_engine.gyp
@@ -28,7 +28,6 @@
     ],
     'defines': [
       '__STDC_FORMAT_MACROS=1',
-      '_FILE_OFFSET_BITS=64',
       '_POSIX_C_SOURCE=199309L',
       'USE_HWID_OVERRIDE=<(USE_hwid_override)',
       'USE_MTD=<(USE_mtd)',