libweave: Put "weave" includes into <>

This style is usually used for external includes.

BUG=brillo:1258
TEST='FEATURES=test emerge-gizmo buffet'

Change-Id: I16ccf70545c593ef530230deda140ecc372715e0
Reviewed-on: https://chromium-review.googlesource.com/290404
Reviewed-by: Vitaly Buka <vitalybuka@chromium.org>
Commit-Queue: Vitaly Buka <vitalybuka@chromium.org>
Trybot-Ready: Vitaly Buka <vitalybuka@chromium.org>
Tested-by: Vitaly Buka <vitalybuka@chromium.org>