fix(hack): use the host CPU model for accelerated aarch64 VMs

The aarch64 dev VM always used -cpu cortex-a57, even with -accel hvf or
-accel kvm. QEMU rejects named CPU models with hvf, and with KVM unless
the host has that CPU, so booting natively on Apple Silicon or an
aarch64 Linux host with KVM failed. Use -cpu host when accelerated.

hack/dev/boot.sh

@@ -15,7 +15,12 @@ set --
 if [ "${TARGET_ARCH}" = "x86_64" ]; then
 	set -- "${@}" qemu-system-x86_64 -M q35 -cpu SandyBridge,vmx=on
 elif [ "${TARGET_ARCH}" = "aarch64" ]; then
+	# Hardware acceleration on aarch64 only supports the host CPU model.
+	if [ -n "${QEMU_ACCEL}" ] && [ "${QEMU_ACCEL}" != "tcg" ]; then
+		set -- "${@}" qemu-system-aarch64 -M virt -cpu host
+	else
 		set -- "${@}" qemu-system-aarch64 -M virt -cpu cortex-a57
+	fi
 fi
 
 if [ -n "${QEMU_ACCEL}" ]; then