clk: socfpga: agilex: add clock driver for the Agilex platform

For the most part the Agilex clock structure is very similar to
Stratix10, so we re-use most of the Stratix10 clock driver.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
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v5: no changes
v4: no changes
v3: Address Stephen Boyd's comments
v2: update to use clk_parent_data
5 files changed