configs: Don't report CPU cores on Fiji properties

ROCm determines if a device is a dGPU in two ways. The first
is by looking at the device ID. The second is through a flag that
gets set only if the reported cpu_cores_count is 0.

If these don't agree, ROCm breaks when doing memory operations.

Previously, cpu_cores_count was non-zero on the Fiji config.
This patch sets it to 0 to appease ROCm

Change-Id: I0fd0ce724f491ed6a4598188b3799468668585f4
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47525
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Matthew Poremba <matthew.poremba@amd.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>

configs/example/hsaTopology.py

@@ -359,7 +359,7 @@ def createFijiTopology(options):
     file_append((io_dir, 'properties'), io_prop)
 
     # Populate GPU node properties
-    node_prop = 'cpu_cores_count %s\n' % options.num_cpus                   + \
+    node_prop = 'cpu_cores_count 0\n'                                       + \
                 'simd_count %s\n'                                             \
                     % (options.num_compute_units * options.simds_per_cu)    + \
                 'mem_banks_count 1\n'                                       + \