dt-bindings: soc: qcom: Remove SPI controller maximum frequency binding

dt-bindings: soc: qcom: Remove SPI controller maximum frequency binding

SPI controller driver should maintain the maximum frequency
of the controller instead of relying on device tree bindings.
Because maximum frequency is specific property of SPI
controller.

Signed-off-by: Dilip Kota <dkota@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alok Chauhan <alokc@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>