Comment 0 for bug 1809488

[Impact]
Booting an armhf guest in EFI mode results in a panic.

[Test Case]
Boot an armhf guest in EFI mode. Here's how I do that on an arm64 box that supports AArch32:

sudo qemu-system-aarch64 -enable-kvm -M virt,gic_version=host -smp 7 -m 2048 -cpu host,aarch64=off -nographic -pflash AAVMF32_CODE.fd -pflash AAVMF32_VARS.fd -drive if=none,file=bionic-server-cloudimg-armhf.img,id=hd0 -device virtio-blk-device,drive=hd0 -drive if=none,file=my-seed.img,id=hd1 -device virtio-blk-device,drive=hd1 -drive if=none,file=debian.img,id=hd3 -device virtio-blk-device,drive=hd3 -netdev type=tap,id=net0 -device virtio-net-device,netdev=net0,mac=<REDACTED>

[Fix]
33412b8673135 efi/arm: Revert deferred unmap of early memmap mapping

[Regression Risk]
This is a regression fix.