feat(rdn2): update power message value to 0

Standalone MM used by RD-N2 platfrom does not have power messaging
support. Set the value to 0.

Signed-off-by: Nishant Sharma <nishant.sharma@arm.com>
Change-Id: Icdb16ea1976ce751071ce3df0e4bd86f3fb8ab8b
diff --git a/plat/arm/board/rdn2/fdts/rdn2_stmm_sel0_manifest.dts b/plat/arm/board/rdn2/fdts/rdn2_stmm_sel0_manifest.dts
index 2cf3f75..6119706 100644
--- a/plat/arm/board/rdn2/fdts/rdn2_stmm_sel0_manifest.dts
+++ b/plat/arm/board/rdn2/fdts/rdn2_stmm_sel0_manifest.dts
@@ -38,7 +38,7 @@
 	xlat-granule = <0>; /* 4KiB */
 	boot-order = <0>;
 	messaging-method = <0x3>; /* Direct request/response supported. */
-	power-management-messages = <0x1>;
+	power-management-messages = <0>;
 	gp-register-num = <0>;
 
 	device-regions {