drm/ttm: Use init_on_free to delay release TTM BOs

Delay release TTM BOs when the kernel default setting is init_on_free.
This offloads the overhead of clearing the system memory to the work
item and potentially a different CPU. This could be very beneficial when
the application does a lot of malloc/free style allocations of system
memory.

Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com&gt;.>
Link: https://patchwork.freedesktop.org/patch/msgid/20230708011355.853-1-rajneesh.bhardwaj@amd.com


Signed-off-by: Christian König <christian.koenig@amd.com>