We have supported per-device dma_map_ops in generic code for a long
time, and this symbol just guards the inclusion of the dma_map_ops
registry used for vmd.  Stop enabling it for anything but vmd.

No change in functionality intended.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NBjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20190410080220.21705-3-hch@lst.deSigned-off-by: NIngo Molnar <mingo@kernel.org>