treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / OPP: Add ti-opp-supply driver

Introduce a ti-opp-supply driver that will use new multiple regulator
support that is part of the OPP core This is needed on TI platforms like
DRA7/AM57 in order to control both CPU regulator and Adaptive Body Bias
(ABB) regulator. These regulators must be scaled in sequence during an
OPP transition depending on whether or not the frequency is being scaled
up or down.

This driver also implements AVS Class0 for these parts by looking up the
required values from registers in the SoC and programming adjusted
optimal voltage values for each OPP.

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

PM / OPP: Move the OPP directory out of power/

The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.

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