refactor(st): use dashes for BSEC node names

This is something commonly asked by Linux kernel DT maintainers [1].
The mentioned doc is not upstreamed, but may be checked with dtbs_check.
While at it align some nodes with Linux or OP-TEE.

[1] https://lore.kernel.org/linux-arm-kernel/20231125184422.12315-1-krzysztof.kozlowski@linaro.org/

Change-Id: I63e983c2a00eda3cd8b81c66c0cd1a97cf8249b7
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/fdts/stm32mp157c-ed1.dts b/fdts/stm32mp157c-ed1.dts
index 949c929..d7bcc84 100644
--- a/fdts/stm32mp157c-ed1.dts
+++ b/fdts/stm32mp157c-ed1.dts
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
 /*
- * Copyright (c) 2017-2023, STMicroelectronics - All Rights Reserved
+ * Copyright (c) 2017-2024, STMicroelectronics - All Rights Reserved
  * Author: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
  */
 /dts-v1/;
@@ -31,7 +31,7 @@
 };
 
 &bsec {
-	board_id: board_id@ec {
+	board_id: board-id@ec {
 		reg = <0xec 0x4>;
 		st,non-secure-otp;
 	};