feat(stm32mp1-fdts): add CoT and fuse references for authentication

Add the stm32mp1 CoT description file. Include the TRUSTED_BOARD_BOOT
entry in the platform device tree file.
Add the missing public root key reference for stm32mp15 and the
encryption key reference for stm32mp13.

Change-Id: I0ae2454979a3df6dd3e4361510317742e8fbc109
Signed-off-by: Lionel Debieve <lionel.debieve@foss.st.com>
diff --git a/fdts/stm32mp131.dtsi b/fdts/stm32mp131.dtsi
index 2c62408..543afa5 100644
--- a/fdts/stm32mp131.dtsi
+++ b/fdts/stm32mp131.dtsi
@@ -455,6 +455,9 @@
 				reg = <0xe4 0xc>;
 				st,non-secure-otp;
 			};
+			enckey_otp: enckey_otp@170 {
+				reg = <0x170 0x10>;
+			};
 		};
 		/*
 		 * Break node order to solve dependency probe issue between