ath79: fix SOC version in compat string for A770

YunCore A770 is based on QCA9531, not QCA9533.

Signed-off-by: Piotr Dymacz <[email protected]>

target/linux/ath79/dts/qca9531_yuncore_a770.dts

@@ -8,7 +8,7 @@
 
 / {
 	model = "YunCore A770";
-	compatible = "yuncore,a770", "qca,qca9533";
+	compatible = "yuncore,a770", "qca,qca9531";
 
 	aliases {
 		led-boot = &status;