arm: stm32mp: spl: add bsec driver in SPL

Add the bsec driver in SPL, as it is needed by SOC part number detection
to found the supported OPP.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp15-u-boot.dtsi b/arch/arm/dts/stm32mp15-u-boot.dtsi
index 1279589..a0d971a 100644
--- a/arch/arm/dts/stm32mp15-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp15-u-boot.dtsi
@@ -65,7 +65,7 @@
 };
 
 &bsec {
-	u-boot,dm-pre-proper;
+	u-boot,dm-pre-reloc;
 };
 
 &clk_csi {