riscv: dts: microchip: remove spi-max-frequency property

Remove the spi-max-frequency property from the spi0 controller
node as it is supposed to be a per SPI peripheral device property.
Reported-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/lkml/20220526014141.2872567-1-robh@kernel.org/Signed-off-by: Nagasuresh Relli <nagasuresh.relli@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>

arch/riscv/boot/dts/microchip/mpfs.dtsi

@@ -278,7 +278,6 @@ spi0: spi@20108000 {
 			interrupt-parent = <&plic>;
 			interrupts = <54>;
 			clocks = <&clkcfg CLK_SPI0>;
-			spi-max-frequency = <25000000>;
 			status = "disabled";
 		};