ARM: dts: exynos4212-tab3: limit usable memory range

The stock bootloader on the Samsung Galaxy Tab 3 8.0 provides an
incorrect available memory range over ATAG_MEM. Limit the usable
memory in the DTS to prevent it from doing so, without having to
disable ATAG support.

Signed-off-by: Artur Weber <[e-mail]>
Reviewed-by: Henrik Grimler <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Krzysztof Kozlowski <[e-mail]>

arch/arm/boot/dts/samsung/exynos4212-tab3.dtsi

···
 		/* Default S-BOOT bootloader loads initramfs here */
 		linux,initrd-start = <0x42000000>;
 		linux,initrd-end = <0x42800000>;
+
+		/*
+		 * Stock bootloader provides incorrect memory size in ATAG_MEM;
+		 * override it here
+		 */
+		linux,usable-memory-range = <0x40000000 0x3fc00000>;
 	};
 
 	firmware@204f000 {