Add support for Airoha AN7581 SoC clock driver. This mainly needed for
eMMC support to correctly get the current clock applied.
Based on the Linux clk-en7523.c but majorly reworked for U-Boot that
doesn't require CCF subsystem.
Major modification, support for set_rate, realtime get_rate and split
for reset part to a different driver.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
