linux-imx

Documentation: PM: Add SPDX license tags to multiple files

Add SPDX license tags to .rst files under Documentation/driver-api/pm
and Documentation/admin-quide/pm.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>