am62a7: dts: Enable full 4GB LPDDR4

AM62A7-SK board has 4GB LPDDR4 Micron MT53E2G32D4DE-046 AUT:B part
but only 2GB was enabled early.

Enable full 4GB memory by updating the latter 2GB memory region
which gets mapped to 0x0880000000 i.e. DDR16SS0_SDRAM as referred in
Table 2-1. AM62A Common SoC Memory of AM62Ax TRM [1].

[1] : https://www.ti.com/lit/zip/spruj16
Logs: https://gist.github.com/devarsht/e85b6af89c01ddadb3a62f3e5f196af8

Signed-off-by: Devarsh Thakkar <devarsht@ti.com>
diff --git a/arch/arm/dts/k3-am62a7-r5-sk.dts b/arch/arm/dts/k3-am62a7-r5-sk.dts
index 7a15b44..c953a82 100644
--- a/arch/arm/dts/k3-am62a7-r5-sk.dts
+++ b/arch/arm/dts/k3-am62a7-r5-sk.dts
@@ -25,7 +25,9 @@
 
 	memory@80000000 {
 		device_type = "memory";
-		reg = <0x00000000 0x80000000 0x00000000 0x80000000>; /* 2G RAM */
+		/* 4G RAM */
+		reg = <0x00000000 0x80000000 0x00000000 0x80000000>,
+		      <0x00000008 0x80000000 0x00000000 0x80000000>;
 		bootph-pre-ram;
 	};
 
diff --git a/arch/arm/dts/k3-am62a7-sk.dts b/arch/arm/dts/k3-am62a7-sk.dts
index 576dbce..b08a083 100644
--- a/arch/arm/dts/k3-am62a7-sk.dts
+++ b/arch/arm/dts/k3-am62a7-sk.dts
@@ -26,8 +26,9 @@
 
 	memory@80000000 {
 		device_type = "memory";
-		/* 2G RAM */
-		reg = <0x00000000 0x80000000 0x00000000 0x80000000>;
+		/* 4G RAM */
+		reg = <0x00000000 0x80000000 0x00000000 0x80000000>,
+		      <0x00000008 0x80000000 0x00000000 0x80000000>;
 	};
 
 	reserved-memory {