clk: mxl: Remove redundant spinlocks

Patch 1/4 of this patch series switches from direct readl/writel
based register access to regmap based register access. Instead
of using direct readl/writel, regmap API's are used to read, write
& read-modify-write clk registers. Regmap API's already use their
own spinlocks to serialize the register accesses across multiple
cores in which case additional driver spinlocks becomes redundant.

Hence, remove redundant spinlocks from driver in this patch 2/4.

Reviewed-by: Yi xin Zhu <yzhu@maxlinear.com>
Signed-off-by: Rahul Tanwar <rtanwar@maxlinear.com>
Link: https://lore.kernel.org/r/a8a02c8773b88924503a9fdaacd37dd2e6488bf3.1665642720.git.rtanwar@maxlinear.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: mxl: Switch from direct readl/writel based IO to regmap based IO

Earlier version of driver used direct io remapped register read
writes using readl/writel. But we need secure boot access which
is only possible when registers are read & written using regmap.
This is because the security bus/hook is written & coupled only
with regmap layer.

Switch the driver from direct readl/writel based register accesses
to regmap based register accesses.

Additionally, update the license headers to latest status.

Reviewed-by: Yi xin Zhu <yzhu@maxlinear.com>
Signed-off-by: Rahul Tanwar <rtanwar@maxlinear.com>
Link: https://lore.kernel.org/r/2610331918206e0e3bd18babb39393a558fb34f9.1665642720.git.rtanwar@maxlinear.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: intel: Use devm_clk_hw_register() instead of clk_hw_register()

To ensure that clks are unregistered in case of any failure, use
devm_clk_hw_register() instead of clk_hw_register().

Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Link: https://lore.kernel.org/r/7ef7009b4e9f986fd6dfbf487c0e85de68a4ba9b.1594880946.git.rahul.tanwar@linux.intel.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

clk: intel: Add CGU clock driver for a new SoC

Clock Generation Unit(CGU) is a new clock controller IP of a forthcoming
Intel network processor SoC named Lightning Mountain(LGM). It provides
programming interfaces to control & configure all CPU & peripheral clocks.
Add common clock framework based clock controller driver for CGU.

Signed-off-by: Rahul Tanwar <rahul.tanwar@linux.intel.com>
Link: https://lkml.kernel.org/r/42a4f71847714df482bacffdcd84341a4052800b.1587102634.git.rahul.tanwar@linux.intel.com
[sboyd@kernel.org: Kill init function to alloc and cleanup newline]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>