drm/amdkfd: Show KFD node memory partition info

Show KFD node memory partition id and size, add helper function
KFD_XCP_MEMORY_SIZE to get kfd node memory size, will be used
later to support memory accounting per partition.

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>