Switch armv7 setting to arm_version==7.

Patch by Mostyn Bramley-Moore <mostynb@opera.com>

BUG=chromium:234135

Review URL: https://breakpad.appspot.com/844002/


git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1246 4c0a9323-5329-0410-9bdc-e9ce6186880e