ARM64: dts: meson-gx: Add firmware reserved memory zones

The Amlogic Meson GXBB/GXL/GXM secure monitor uses part of the memory space,
this patch adds these reserved zones.

Without such reserved memory zones, running the following stress command :
$ stress-ng --vm 16 --vm-bytes 128M --timeout 10s
multiple times:

Could lead to the following kernel crashes :
[   46.937975] Bad mode in Error handler detected on CPU1, code 0xbf000000 -- SError
...
[   47.058536] Internal error: Attempting to execute userspace memory: 8600000f [#3] PREEMPT SMP
...
Instead of the OOM killer.

Fixes: 4f24eda ("ARM64: dts: Prepare configs for Amlogic Meson GXBaby")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
[khilman: added Fixes tag, added _reserved and unit addresses]
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/boot/dts/amlogic/meson-gx.dtsi

@@ -55,6 +55,24 @@
 	#address-cells = <2>;
 	#size-cells = <2>;
 
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <2>;
+		ranges;
+
+		/* 16 MiB reserved for Hardware ROM Firmware */
+		hwrom_reserved: hwrom@0 {
+			reg = <0x0 0x0 0x0 0x1000000>;
+			no-map;
+		};
+
+		/* 2 MiB reserved for ARM Trusted Firmware (BL31) */
+		secmon_reserved: secmon@10000000 {
+			reg = <0x0 0x10000000 0x0 0x200000>;
+			no-map;
+		};
+	};
+
 	cpus {
 		#address-cells = <0x2>;
 		#size-cells = <0x0>;