Moves it to the hypervisor leafs.
Before:
```bash
$ FEXBash 'cat /proc/cpuinfo | grep "model name"'
model name : FEX-2404-101-gf9effcb Cortex-A78C
model name : FEX-2404-101-gf9effcb Cortex-A78C
model name : FEX-2404-101-gf9effcb Cortex-A78C
model name : FEX-2404-101-gf9effcb Cortex-A78C
model name : FEX-2404-101-gf9effcb Cortex-X1C
model name : FEX-2404-101-gf9effcb Cortex-X1C
model name : FEX-2404-101-gf9effcb Cortex-X1C
model name : FEX-2404-101-gf9effcb Cortex-X1C
```
After:
```bash
$ FEXBash 'cat /proc/cpuinfo | grep "model name"'
model name : Cortex-A78C
model name : Cortex-A78C
model name : Cortex-A78C
model name : Cortex-A78C
model name : Cortex-X1C
model name : Cortex-X1C
model name : Cortex-X1C
model name : Cortex-X1C
```
Now the FEX string is in the hypervisor functions as a leaf, so if some
utility wants the FEX version they can query that directly
Ex:
```bash
$ ./Bin/FEXInterpreter get_cpuid_fex
Maximum 4000_0001h sub-leaf: 2
We are running under FEX on host: 2
FEX version string is: 'FEX-2404-113-g820494d'
```
Exposes the host architecture through this CPUID function. Only exposes
the architectures we support. Not burning 16-bits on using ELF machine
definitions here.
Uses 4 bits still for future expansion.