staging: hikey9xx: hi6421-spmi-pmic: update copyright

Remove the GPL boilerplate, as SPDX tag already points to the
license terms and add a new copyright for Huawei.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/18b36d01c04519d84912140b6c40c1bd1f75a3a8.1611212783.git.mchehab+huawei@kernel.org


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