clk: imx: Support building i.MX common clock driver as module

There are more and more requirements of building SoC specific drivers
as modules, add support for building i.MX common clock driver as module
to meet the requirement.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 460

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation http www opensource org
licenses gpl license html http www gnu org copyleft gpl html

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 3 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081201.897982733@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

clk: imx: clk-cpu: Switch to clk_hw based API

Switch the clk_cpu clock registering function to clk_hw based API and add
a macro for clk based legacy. This allows us to move closer to a clear
split between consumer and provider clk APIs.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

clk: imx: cpu clock should be always critical

Add CLK_IS_CRITICAL flag for cpu clock type to
make cpu clock use count correct, as cpu clock
should be always critical.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: imx: clk-cpu: Include "clk.h" header file

Include the "clk.h" header file to fix the following sparse warning:

drivers/clk/imx/clk-cpu.c:77:12: warning: symbol 'imx_clk_cpu' was not declared. Should it be static?

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

ARM: imx: move clock drivers into drivers/clk

After the cleanup on clock drivers, they are now ready to be moved into
drivers/clk. Let's move them into drivers/clk/imx folder.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>