ARM: dts: stm32: Use DT alias for the configuration EEPROM

Use DT /aliases node to establish a stable phandle to the configuration
EEPROM. This permits the configuration EEPROM to be moved e.g. to a
different address or a different bus. Adjust the board code to handle
new phandle lookup.

Reviewed-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp15xx-dhcom.dtsi b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
index bed69c9..e5be0a7 100644
--- a/arch/arm/dts/stm32mp15xx-dhcom.dtsi
+++ b/arch/arm/dts/stm32mp15xx-dhcom.dtsi
@@ -10,6 +10,10 @@
 #include <dt-bindings/mfd/st,stpmic1.h>
 
 / {
+	aliases {
+		eeprom0 = &eeprom0;
+	};
+
 	memory@c0000000 {
 		device_type = "memory";
 		reg = <0xC0000000 0x40000000>;
@@ -187,7 +191,7 @@
 		};
 	};
 
-	eeprom@50 {
+	eeprom0: eeprom@50 {
 		compatible = "atmel,24c02";
 		reg = <0x50>;
 		pagesize = <16>;