ARM: dts: at91: at91sam9261ek: fix SPI unit address warning

w+arch/arm/dts/.at91sam9261ek.dtb.pre.tmp:124.15-144.7: Warning (spi_bus_reg): /ahb/apb/spi@fffc8000/tsc2046@0: SPI bus unit address format error, expected "2"
Signed-off-by: NEugen Hristev <eugen.hristev@microchip.com>

arch/arm/dts/at91sam9261ek.dts

@@ -121,7 +121,7 @@
 					spi-max-frequency = <15000000>;
 				};
 
-				tsc2046@0 {
+				tsc2046@2 {
 					reg = <2>;
 					compatible = "ti,ads7843";
 					interrupts-extended = <&pioC 2 IRQ_TYPE_EDGE_BOTH>;