Add a config capable of simulating MI300X ISA (gfx942). This is similar
to the mi200.py config and uses the same scripts followed by some
tuneable parameters. This config optionally lets the user call the
runMI300GPU function with gem5 resources. This allows for something like
the following before a VIPER stdlib python is available:
```
import mi300
from gem5.resources.resource import obtain_resource
disk = obtain_resource("x86-gpu-fs-img")
kernel = obtain_resource("x86-linux-kernel-5.4.0-105-generic")
app = obtain_resource("square-gpu-test")
mi300.runMI300GPUFS("X86KvmCPU", disk, kernel, app)
```
Tested cold boot config, checkpoint create and restore, and using gem5
resources.
Change-Id: I50a13d7a3d207786b779bf7fd47a5645256b1e6a