staging: hikey9xx: hisilicon, hisi-spmi-controller.yaml fix bindings

Fix a few warnings produced by make dt_binding_check.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/fca7260e7c61f073ae376ab23f58856ba5a87a7a.1611212783.git.mchehab+huawei@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>