K 10
svn:author
V 2
br
K 8
svn:date
V 27
2020-08-05T19:11:31.917639Z
K 7
svn:log
V 290
o Add machine/iommu.h and include MD iommu headers from it,
  so we don't ifdef for every arch in busdma_iommu.c;
o No need to include specialreg.h for x86, remove it.

Requested by:	andrew
Reviewed by:	kib
Sponsored by:	DARPA/AFRL
Differential Revision:	https://reviews.freebsd.org/D25957

END