arm64: dts: qcom: qcm6490-fairphone-fp5: Add missing reserved-memory

It seems we also need to reserve a region of 81 MiB called "removed_mem"
otherwise we can easily hit the following error with higher RAM usage:

  [ 1467.809274] Internal error: synchronous external abort: 0000000096000010 [#2] SMP

Fixes: eee9602 ("arm64: dts: qcom: qcm6490: Add device-tree for Fairphone 5")
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20231229-fp5-reserved-mem-v1-1-87bb818f1397@fairphone.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>

arch/arm64/boot/dts/qcom/qcm6490-fairphone-fp5.dts

@@ -82,6 +82,11 @@
 			no-map;
 		};
 
+		removed_mem: removed@c0000000 {
+			reg = <0x0 0xc0000000 0x0 0x5100000>;
+			no-map;
+		};
+
 		rmtfs_mem: memory@f8500000 {
 			compatible = "qcom,rmtfs-mem";
 			reg = <0x0 0xf8500000 0x0 0x600000>;