ARM: dts: bcm: Fix SPI bus warnings

dtc has new checks for SPI buses. Fix the warnings in node names.

arch/arm/boot/dts/bcm53340-ubnt-unifi-switch8.dtb: Warning (spi_bus_bridge): /axi@18000000/qspi@27200: node name for SPI buses should be 'spi'
arch/arm/boot/dts/bcm958525er.dtb: Warning (spi_bus_bridge): /axi/qspi@27200: node name for SPI buses should be 'spi'
arch/arm/boot/dts/bcm958525xmc.dtb: Warning (spi_bus_bridge): /axi/qspi@27200: node name for SPI buses should be 'spi'
arch/arm/boot/dts/bcm958622hr.dtb: Warning (spi_bus_bridge): /axi/qspi@27200: node name for SPI buses should be 'spi'
arch/arm/boot/dts/bcm958625hr.dtb: Warning (spi_bus_bridge): /axi/qspi@27200: node name for SPI buses should be 'spi'
arch/arm/boot/dts/bcm988312hr.dtb: Warning (spi_bus_bridge): /axi/qspi@27200: node name for SPI buses should be 'spi'

Cc: Ray Jui <[e-mail]>
Cc: Scott Branden <[e-mail]>
Cc: Jon Mason <[e-mail]>
Cc: [e-mail]
Signed-off-by: Rob Herring <[e-mail]>
Signed-off-by: Florian Fainelli <[e-mail]>

arch/arm/boot/dts/bcm-hr2.dtsi

···
 			reg = <0x33000 0x14>;
 		};
 
-		qspi: qspi@27200 {
+		qspi: spi@27200 {
 			compatible = "brcm,spi-bcm-qspi", "brcm,spi-nsp-qspi";
 			reg = <0x027200 0x184>,
 			      <0x027000 0x124>,

arch/arm/boot/dts/bcm-nsp.dtsi

···
 			brcm,nand-has-wp;
 		};
 
-		qspi: qspi@27200 {
+		qspi: spi@27200 {
 			compatible = "brcm,spi-bcm-qspi", "brcm,spi-nsp-qspi";
 			reg = <0x027200 0x184>,
 			      <0x027000 0x124>,