rocr/kfd-driver: Add initial KFD driver interface

Adds the initial KFD driver interface and use it to open the
KFD from amd_topology.cpp.

This change is to show the direction of the Driver interface for
initially supporting the KFD and to get feedback on the approach.
For now we wrap relevant ROCt calls behind this generic driver
interface so that we can generalize core ROCr components like
MemoryRegion, Runtime, etc.

Now that ROCt is incorporated into ROCr, we can more fully integrate
ROCt into the Driver interface. Ideally, we get to a point where
the generic Driver interface can support KFD, XDNA, and potential
future drivers.

Change-Id: I4573fd6af1f8398233ee9d3814d9f3139dd0279c

runtime/hsa-runtime/core/runtime/amd_topology.cpp

@@ -74,7 +74,7 @@ static const uint kKfdVersionMinor = 99;
 
 void DiscoverDrivers(bool &gpu_found, bool &aie_found) {
   // Open connection to GPU and AIE kernel drivers.
-  gpu_found = (hsaKmtOpenKFD() == HSAKMT_STATUS_SUCCESS);
+  gpu_found = (KfdDriver::DiscoverDriver() == HSA_STATUS_SUCCESS);
   aie_found = (XdnaDriver::DiscoverDriver() == HSA_STATUS_SUCCESS);
 }