dma-buf/sw-sync: sync_pt is private and of fixed size

dma-buf/sw-sync: sync_pt is private and of fixed size

Since sync_pt is only allocated from a single location and is no longer
the base class for fences (that is struct dma_fence) it no longer needs
a generic unsized allocator.

Signed-off-by: Chris Wilson <[email protected]>
Cc: Sumit Semwal <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Reviewed-by: Sean Paul <[email protected]>
Signed-off-by: Gustavo Padovan <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]