drm/amdkfd: CRIU Discover svm ranges

A KFD process may contain a number of virtual address ranges for shared
virtual memory management and each such range can have many SVM
attributes spanning across various nodes within the process boundary.
This change reports the total number of such SVM ranges and
their total private data size by extending the PROCESS_INFO op of the the
CRIU IOCTL to discover the svm ranges in the target process and a future
patches brings in the required support for checkpoint and restore for
SVM ranges.

Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>