arm64: dts: qcom: msm8996: add glink-edge nodes

MSM8996 provides limited glink support, so add corresponding device tree
nodes. For example the following interfaces are provided on db820c:

modem:
2080000.remoteproc:glink-edge.LOOPBACK_CTL_MPSS.-1.-1
2080000.remoteproc:glink-edge.glink_ssr.-1.-1
2080000.remoteproc:glink-edge.rpmsg_chrdev.0.0

adsp:
9300000.remoteproc:glink-edge.LOOPBACK_CTL_LPASS.-1.-1
9300000.remoteproc:glink-edge.glink_ssr.-1.-1
9300000.remoteproc:glink-edge.rpmsg_chrdev.0.0

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>