ARM: dts: aspeed: p10bmc: Enable KCS channel 2

Rainier uses KCS channel 2 as the source for the debug-trigger
application outlined at [1] and implemented at [2].

[1] https://github.com/openbmc/docs/blob/master/designs/bmc-service-failure-debug-and-recovery.md
[2] https://github.com/openbmc/debug-triggerSigned-off-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20210623033854.587464-8-andrew@aj.id.auSigned-off-by: Joel Stanley <joel@jms.id.au>

arch/arm/boot/dts/aspeed-bmc-ibm-everest.dts

@@ -3646,6 +3646,11 @@ &xdma {
 	memory-region = <&vga_memory>;
 };
 
+&kcs2 {
+	status = "okay";
+	aspeed,lpc-io-reg = <0xca8 0xcac>;
+};
+
 &kcs3 {
 	status = "okay";
 	aspeed,lpc-io-reg = <0xca2>;

arch/arm/boot/dts/aspeed-bmc-ibm-rainier.dts

@@ -2380,6 +2380,11 @@ &xdma {
 	memory-region = <&vga_memory>;
 };
 
+&kcs2 {
+	status = "okay";
+	aspeed,lpc-io-reg = <0xca8 0xcac>;
+};
+
 &kcs3 {
 	status = "okay";
 	aspeed,lpc-io-reg = <0xca2>;