default.xml: update to YP 3.1.6

default.xml: update to YP 3.1.6

Update poky to the include the yocto-3.1.6 revision plus an additional
required bugfix commit that missed the release tag, and also uprev the
meta-openembedded, meta-virtualization, and meta-raspberrypi layers to
their latest dunfell revisions to pick up fixes.  Updates to community
supported hardware BSP layers will be addressed separately at a later
time.

Bug-AGL: SPEC-3840

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: Ib386314a119c16679123987b9f19a09a6cb9240c
(cherry picked from commit 61d7b1e5af777e6ff7bfd6a860faf8125e2b8881)