Add AXS10X I2S PLL clock driver

The ARC SDP I2S clock can be programmed using a
specific PLL.

This patch series has the goal of adding a clock driver that programs this PLL.

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Changes v5 -> v6:
* Use parent clock to determine PLL input rate instead of using hardcoded values
* Documentation update (added 'clocks' field)
* Device tree update (added 'clocks' field)

Changes v4 -> v5:
* Documentation update (as suggested by Alexey Brodkin)
* Changed compatible string to "snps,axs10x-i2s-pll-clock" (as suggested by Alexey Brodkin)
* Added DT bindings

Changes v3 -> v4:
* Added binding document (as suggested by Stephen Boyd)
* Minor code style fixes (as suggested by Stephen Boyd)
* Use ioremap (as suggested by Stephen Boyd)
* Implement round_rate (as suggested by Stephen Boyd)
* Change to platform driver (as suggested by Stephen Boyd)
* Use {readl/writel}_relaxed (as suggested by Vineet Gupta)

Changes v2 -> v3:
* Implemented recalc_rate

Changes v1 -> v2:
* Renamed folder to axs10x (as suggested by Alexey Brodkin)
* Added more supported rates

Jose Abreu (2):
clk/axs10x: Add I2S PLL clock driver
arc: axs10x: Add DT bindings for I2S PLL Clock

 .../bindings/clock/axs10x-i2s-pll-clock.txt        |  25 +++
 arch/arc/boot/dts/axs10x_mb.dtsi                   |  13 ++
 drivers/clk/Makefile                               |   1 +
 drivers/clk/axs10x/Makefile                        |   1 +
 drivers/clk/axs10x/i2s_pll_clock.c                 | 228 +++++++++++++++++++++
 5 files changed, 268 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
 create mode 100644 drivers/clk/axs10x/Makefile
 create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c

1.9.1