ARM: dts: BCM5301X: Use updated "spi-gpio" binding properties

ARM: dts: BCM5301X: Use updated "spi-gpio" binding properties

Switch away from deprecated properties.

This fixes:
arch/arm/boot/dts/bcm4708-buffalo-wzr-1750dhp.dtb: spi: gpio-sck: False schema does not allow [[6, 7, 0]]
        From schema: Documentation/devicetree/bindings/spi/spi-gpio.yaml
arch/arm/boot/dts/bcm4708-buffalo-wzr-1750dhp.dtb: spi: gpio-mosi: False schema does not allow [[6, 4, 0]]
        From schema: Documentation/devicetree/bindings/spi/spi-gpio.yaml
arch/arm/boot/dts/bcm4708-buffalo-wzr-1750dhp.dtb: spi: 'sck-gpios' is a required property
        From schema: Documentation/devicetree/bindings/spi/spi-gpio.yaml
arch/arm/boot/dts/bcm4708-buffalo-wzr-1750dhp.dtb: spi: Unevaluated properties are not allowed ('gpio-mosi', 'gpio-sck' were unexpected)
        From schema: Documentation/devicetree/bindings/spi/spi-gpio.yaml

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20230602151023.8607-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>