kernel/dma.c: remove a CVS keyword

Remove a CVS keyword that wasn't updated for a long time from a comment.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/dma.c

-/* $Id: dma.c,v 1.7 1994/12/28 03:35:33 root Exp root $
+/*
  * linux/kernel/dma.c: A DMA channel allocator. Inspired by linux/kernel/irq.c.
  *
  * Written by Hennus Bergman, 1992.