Set target_subarch=both on Chromium FYI iOS ninja bot

Set target_subarch=both on Chromium FYI iOS ninja bot

Note that target_subarch=both is already set on the tryserver and Mac main waterfalls.

BUG=458398
Committed: https://crrev.com/d3783da2a36ff31175479eae4dac0eacd94ba35e
Cr-Commit-Position: refs/heads/master@{#316910}

[smut, 2015-02-13 02:27:32]

smut@google.com changed reviewers:
+ sdefresne@chromium.org, stip@chromium.org

[sdefresne, 2015-02-13 09:35:27]

lgtm

[smut, 2015-02-18 20:49:07]

The CQ bit was checked by smut@google.com

[smut, 2015-02-18 20:49:11]

The CQ bit was unchecked by smut@google.com

[smut, 2015-02-18 22:04:59]

The CQ bit was checked by smut@google.com

[commit-bot: I haz the power, 2015-02-18 22:06:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/926443002/1

[commit-bot: I haz the power, 2015-02-18 23:02:27]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-18 23:03:31]

Patchset 1 (id:??) landed as
https://crrev.com/d3783da2a36ff31175479eae4dac0eacd94ba35e
Cr-Commit-Position: refs/heads/master@{#316910}