agl-compositor: Bump SRCREV

agl-compositor: Bump SRCREV

This bumps up SRCREV to include 'compositor: Do not allow vt-switching
by default'.

Note this patch also includes

- re-building libweston with headless backend as lamprey was cut after
  some of the changes made into agl-compositor and it those it requires
  having the headless backend installed

- includes the libcompositor updates required to avoid QA build errors

- compliance with weston ini configuration wrt to loading up systemd
  plugin.

Bug-AGL: SPEC-4063

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: I9abbb84895de2e37d814ff0485ae0d004982fc34
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/26604
Tested-by: Jenkins Job builder account
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>