dma-mapping: remove deprecated dma_sync_single and dma_sync_sg API

Since 2.6.5, it had been commented, 'for backwards compatibility,
removed in 2.7.x'. Since 2.6.31, it have been marked as __deprecated.

I think that we can remove the API safely now.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>