feat(st): update STM32MP DT files

This is an alignment with Linux DT files that have been merged in
stm32 tree [1], and will be in Linux 6.7.
The /omit-if-no-ref/ in overlay files are now removed, as already in
pinctrl files.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/atorgue/stm32.git

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: Iab94b0ba7a4a0288ca53d1ae57ab590566967415
diff --git a/fdts/stm32mp157a-dk1.dts b/fdts/stm32mp157a-dk1.dts
index a73bef8..b4d5d20 100644
--- a/fdts/stm32mp157a-dk1.dts
+++ b/fdts/stm32mp157a-dk1.dts
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
 /*
- * Copyright (C) STMicroelectronics 2019 - All Rights Reserved
+ * Copyright (C) 2019-2023, STMicroelectronics - All Rights Reserved
  * Author: Alexandre Torgue <alexandre.torgue@st.com> for STMicroelectronics.
  */
 
@@ -15,12 +15,6 @@
 	model = "STMicroelectronics STM32MP157A-DK1 Discovery Board";
 	compatible = "st,stm32mp157a-dk1", "st,stm32mp157";
 
-	aliases {
-		serial0 = &uart4;
-		serial1 = &usart3;
-		serial2 = &uart7;
-	};
-
 	chosen {
 		stdout-path = "serial0:115200n8";
 	};