[PARISC] Use page allocator instead of slab allocator in pci-dma.c

Slab pages obtained via kmalloc are not cacheline aligned.  Nor is it
advisable to perform VM operations designed for page allocator pages on
memory obtained via kmalloc.

So replace the page sized allocations in kernel/pci-dma.c with page allocator
pages.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>