drm/amdkfd: Reorganize CRAT fetching from ACPI

Reorganize and rename kfd_topology_get_crat_acpi function. In this way
acpi_get_table(..) needs to be called only once. This will also aid in
dGPU topology implementation.

Signed-off-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Kent Russell <kent.russell@amd.com>
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>