[PATCH 2/2] powerpc: Remove map_/unmap_single() from dma_mapping_ops

[Becky Bruce]

| 
| Now that all of the remaining dma_mapping_ops have had their
| map_/unmap_single
| functions updated to become map/unmap_page functions, there is no need
| to have
| the map_/unmap_single function pointers in the dma_mapping_ops.
| 
| So, take this opportunity to remove them and also remove the code that
| does
| the checking for which set of functions to use.
| 
| Signed-off-by: Mark Nelson <markn at au1.ibm.com>

LGTM; test-built and booted an 8641 to double check.  I'm glad to see
the hackery removed. 

Acked-by: Becky Bruce <becky.bruce at freescale.com>

Cheers,
-Becky