ttm: Expand (*populate) to support an array of DMA addresses.

We pass in the array of ttm pages to be populated in the GART/MM
of the card (or AGP). Patch titled: "ttm: Utilize the DMA API for
pages that have TTM_PAGE_FLAG_DMA32 set." uses the DMA API to make
those pages have a proper DMA addresses (in the situation where
page_to_phys or virt_to_phys do not give use the DMA (bus) address).

Since we are using the DMA API on those pages, we should pass in the
DMA address to this function so it can save it in its proper fields
(later patches use it).

[v2: Added reviewed-by tag]

Reviewed-by: Thomas Hellstrom <thellstrom@shipmail.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Ian Campbell <ian.campbell@citrix.com>