[arm] Fix an accessor return type.

[arm] Fix an accessor return type.

Existing uses are correct but the return type was misleading.

Also clarify some related comments to make the difference between Bits
and BitField more obvious.

BUG=

Committed: https://crrev.com/a338dad442e4a22c8d8f53e6351d2fb640fbbfb2
Cr-Commit-Position: refs/heads/master@{#38894}

[jbramley, 2016-08-24 12:46:40]

jacob.bramley@arm.com changed reviewers:
+ bmeurer@chromium.org, epertoso@chromium.org, jarin@chromium.org

[Benedikt Meurer, 2016-08-24 17:40:16]

lgtm

[jbramley, 2016-08-25 08:41:05]

The CQ bit was checked by jacob.bramley@arm.com

[commit-bot: I haz the power, 2016-08-25 08:41:13]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-08-25 09:05:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-08-25 09:05:28]

Description was changed from

==========
[arm] Fix an accessor return type.

Existing uses are correct but the return type was misleading.

Also clarify some related comments to make the difference between Bits
and BitField more obvious.

BUG=
==========

to

==========
[arm] Fix an accessor return type.

Existing uses are correct but the return type was misleading.

Also clarify some related comments to make the difference between Bits
and BitField more obvious.

BUG=

Committed: https://crrev.com/a338dad442e4a22c8d8f53e6351d2fb640fbbfb2
Cr-Commit-Position: refs/heads/master@{#38894}
==========

[commit-bot: I haz the power, 2016-08-25 09:05:29]

Patchset 1 (id:??) landed as
https://crrev.com/a338dad442e4a22c8d8f53e6351d2fb640fbbfb2
Cr-Commit-Position: refs/heads/master@{#38894}