drivers/dma/Kconfig: add part number for Topcliff.

Product codenames are OK, but once an actual product name is available,
it should be referenced as well.

  http://ark.intel.com/chipset.aspx?familyID=52499



Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>