spi: qup: Parse OPP table for DVFS support

spi: qup: Parse OPP table for DVFS support

Parse the OPP table from the device tree and use dev_pm_opp_set_rate()
instead of clk_set_rate() to allow making performance state for power
domains specified in the OPP table.

This is needed to guarantee correct behavior of the clock, especially
with the higher clock/SPI bus frequencies.

Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Link: https://lore.kernel.org/r/20230919-spi-qup-dvfs-v2-2-1bac2e9ab8db@kernkonzept.com
Signed-off-by: Mark Brown <broonie@kernel.org>