feat(stm32mp1): add NVMEM layout compatibility definition

Used by driver parsing this node to get information.

Change-Id: I50623a497157adf7b9da6fafe8d79f6ff58c0ebc
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index c63efd5..5d41898 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -486,6 +486,7 @@
 #define DT_BSEC_COMPAT			"st,stm32mp15-bsec"
 #define DT_DDR_COMPAT			"st,stm32mp1-ddr"
 #define DT_IWDG_COMPAT			"st,stm32mp1-iwdg"
+#define DT_NVMEM_LAYOUT_COMPAT		"st,stm32-nvmem-layout"
 #define DT_PWR_COMPAT			"st,stm32mp1,pwr-reg"
 #define DT_RCC_CLK_COMPAT		"st,stm32mp1-rcc"