Start CPU at EL2 in ARM bootloader when nestedVirtualization=true

Nobody has claimed this yet.

**Describe the solution you'd like**

The EFI bootloader on WSL on ARM starts the CPU at EL1.

`[ 0.255558] CPU: All CPU(s) started at EL1
`

This prevents the WSL kernel from enabling HYP mode:

```
[hayden@~]$ dmesg | grep -i kvm
[ 0.528909] kvm [1]: HYP mode not available
```

And this prevents utilizing KVM on WSL on ARM, with a custom kernel built [with KVM enabled](https://gist.github.com/sirredbeard/0865b5b9bd1635c297f5ee8002798734):

```
[hayden@~]$ qemu-system-aarch64 -machine virt -cdrom ubuntu-22.04.2-live-server-arm64.iso -net nic -net user -boot d -m 1024 -bios /usr/share/qemu/linuxboot_dma.bin -enable-kvm
Could not access KVM kernel module: No such file or directory
qemu-system-aarch64: failed to initialize kvm: No such file or directory
```

```
:~ # qemu-system-aarch64 -m 2048 -cpu cortex-a57 -smp 2 -M virt -bios /usr/share/qemu/qemu-uefi-aarch64.bin -drive if=none,file=openSUSE-Tumbleweed-ARM-JeOS-efi.aarch64.raw,id=hd0 -device virtio-blk-device,drive=hd0 -enable-kvm
Could not access KVM kernel module: No such file or directory
qemu-system-aarch64: failed to initialize kvm: No such file or directory
```

The nestedVirtualization setting in .wslconfig should boot the CPU as EL2 (or, optionally, enabling HYP mode), enabling KVM on WSL on ARM.

**Describe alternatives you've considered**

Without KVM, virtualization can still be achieved in usermode, but without KVM acceleration.

Start by tracing the ARM EFI bootloader behavior controlled by the nestedVirtualization setting in .wslconfig. Reproduce the current state with dmesg and the provided qemu-system-aarch64 commands; done means the CPU starts at EL2 and KVM is available on WSL on ARM.

Written by the indexing model from the issue text.