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

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: eee9602ad649 ("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>