Update git submodules

Update git submodules

* Update swift from branch 'master'
  to bf1e370b2892b7615a96517d2e156f57efea8933
  - test_relinker.py: fix delta timestamp setup

    The related change didn't sufficiently prepare the tests for
    timestamps that have offset hex parts. When adding a delta to a
    timestamp we need to preserve the original timestamp's hex part and
    adjust the float part by the delta amount.

    Related-Change: Id214c965c4fd6f96889fc2fd4ec709cb8987726a

    Change-Id: If8e98c5e088cecf44805bb6c3d1f20a2b6fc56c2
    Signed-off-by: Alistair Coles <alistairncoles@gmail.com>