drop BASE_VER define

The libchrome pc files export BASE_VER define themselves now, so no
need for us to do it.

BUG=chromium:331128
TEST=`cbuildbot chromiumos-sdk` still works

Change-Id: I3301ad41f3dc6399a8fa65a5edf66080454a91e7
Reviewed-on: https://chromium-review.googlesource.com/185062
Reviewed-by: Daniel Erat <derat@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed