Init all fields in ttm_resource_alloc() when we create a new resource.

v2: use place->mem_type instead of res->mem_type
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210430092508.60710-2-christian.koenig@amd.com