ARM: dts: qcom: msm8960: drop spi-max-frequency from controller

spi-max-frequency is a property of SPI device, not SPI controller.  Drop
it from the controller nodes.  No functional impact expected, although
qcom-msm8960-samsung-expressatt board does not have any child SPI
devices thus the property disappears.  This fixes dtbs_check warnings
like:

  qcom-msm8960-cdp.dtb: spi@16080000: Unevaluated properties are not allowed ('spi-max-frequency' was unexpected)
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230619170151.65505-4-krzysztof.kozlowski@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm/boot/dts/qcom/qcom-msm8960.dtsi

@@ -364,7 +364,6 @@ gsbi1_spi: spi@16080000 {
 				#size-cells = <0>;
 				reg = <0x16080000 0x1000>;
 				interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
-				spi-max-frequency = <24000000>;
 				cs-gpios = <&msmgpio 8 0>;
 
 				clocks = <&gcc GSBI1_QUP_CLK>, <&gcc GSBI1_H_CLK>;