arm: dts: stm32: Align stm32mp15xx-*-scmi-u-boot.dtsi file

Update "secure" version of STM32 boards based on SCMI when RCC_TZCR.TZEN=1
stm32mp15xx-*-scmi-u-boot.dtsi with latest patches on files
stm32mp15xx-*-u-boot.dtsi.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/dts/stm32mp157c-dk2-scmi-u-boot.dtsi b/arch/arm/dts/stm32mp157c-dk2-scmi-u-boot.dtsi
index 5a8fc15..ae93497 100644
--- a/arch/arm/dts/stm32mp157c-dk2-scmi-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157c-dk2-scmi-u-boot.dtsi
@@ -4,3 +4,10 @@
  */
 
 #include "stm32mp157a-dk1-scmi-u-boot.dtsi"
+
+/ {
+	fwu-mdata {
+		compatible = "u-boot,fwu-mdata-gpt";
+		fwu-mdata-store = <&sdmmc1>;
+	};
+};