ARM: dts: samsung: exynos4412: decrease memory to account for unusable region

The last 4 MiB of RAM on those devices is likely used by trustzone
firmware, and is unusable under Linux. Change the device tree memory
node accordingly.

The proprietary bootloader (S-BOOT) passes these memory ranges through
ATAG_MEM; this change allows us to have the correct memory ranges
without relying on ATAG_MEM.

Tested-by: Henrik Grimler <henrik@grimler.se> # i9300, i9305
Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Link: https://lore.kernel.org/r/20240217-exynos4-memsize-fix-v1-1-7858e9c5f844@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: refractionware

arch/arm/boot/dts/samsung/exynos4412-i9300.dts

@@ -18,7 +18,7 @@
 
 	memory@40000000 {
 		device_type = "memory";
-		reg = <0x40000000 0x40000000>;
+		reg = <0x40000000 0x3fc00000>;
 	};
 };
 

arch/arm/boot/dts/samsung/exynos4412-i9305.dts

@@ -11,7 +11,7 @@
 
 	memory@40000000 {
 		device_type = "memory";
-		reg = <0x40000000 0x80000000>;
+		reg = <0x40000000 0x7fc00000>;
 	};
 };
 

arch/arm/boot/dts/samsung/exynos4412-n710x.dts

@@ -9,7 +9,7 @@
 
 	memory@40000000 {
 		device_type = "memory";
-		reg = <0x40000000 0x80000000>;
+		reg = <0x40000000 0x7fc00000>;
 	};
 
 	/* bootargs are passed in by bootloader */

arch/arm/boot/dts/samsung/exynos4412-p4note.dtsi

@@ -23,7 +23,7 @@
 
 	memory@40000000 {
 		device_type = "memory";
-		reg = <0x40000000 0x80000000>;
+		reg = <0x40000000 0x7fc00000>;
 	};
 
 	aliases {