[POWERPC] Remove bogus comment in dma_direct_alloc_coherent()

Since commit c80d9133e99de1af607314107910a2a1645efb17 (Make direct DMA use
node local allocations) went in this comment makes no sense.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/dma_64.c

@@ -130,7 +130,6 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 	void *ret;
 	int node = dev->archdata.numa_node;
 
-	/* TODO: Maybe use the numa node here too ? */
 	page = alloc_pages_node(node, flag, get_order(size));
 	if (page == NULL)
 		return NULL;