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>

clk: pxa: add pxa3xx clock driver

Move pxa25x clock drivers from arch/arm/mach-pxa to driver/clk.
In the move :
- convert to new clock framework legacy clocks
- provide clocks as before for platform data based boards
- provide clocks through devicetree with clk-pxa-dt

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

clk: add pxa25x clock drivers

Move pxa25x clock drivers from arch/arm/mach-pxa to driver/clk.
In the move :
- convert to new clock framework legacy clocks
- provide clocks as before for platform data based boards
- provide clocks through devicetree with clk-pxa-dt

This is the preliminary step in the conversion. The remaining steps are
:
- pxa3xx
- once PXA is fully converted to device tree, if that happens,
clk-pxa2* and clk-pxa3* should only hold the core clocks which cannot
be described in devicetree.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Tested-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

clk: add pxa27x clock drivers

Move pxa27x clock drivers from arch/arm/mach-pxa to driver/clk.
In the move :
- convert to new clock framework legacy clocks
- provide clocks as before for platform data based boards
- provide clocks through devicetree

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

clk: add pxa clocks infrastructure

Add a the common code used by all PXA variants.

This is the first step in the transition from architecture defined
clocks (in arch/arm/mach-pxa) towards clock framework. The goal is to
have the same features (and not all the features) of the existing
clocks, and enable the transition of PXA to device-tree.

All PXA rely on a "CKEN" type clock, which :
- has a gate (bit in CKEN register)
- is generated from a PLL, generally divided
- has an alternate low power clock

Each variant will specialize the CKEN clock :
- pxa25x have no low power clock
- pxa27x in low power use always the 13 MHz ring oscillator
- pxa3xx in low power have specific dividers for each clock

The device-tree provides a list of CLK_* (ex: CLK_USB or CLK_I2C) to get
a handle on the clock. While pxa-clock.h will describe all the clocks of
all the variants, each variant will only use a subset of it.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Mike Turquette <mturquette@linaro.org>