vfio/iova_bitmap: Export more API symbols

mainline inclusion
from mainline-v6.7-rc1
commit 53f0b020218fcc0a56a11df39630dbd379e4d9a6
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I8Y6AM
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?53f0b020218fcc0a56a11df39630dbd379e4d9a6

--------------------------------

In preparation to move iova_bitmap into iommufd, export the rest of API
symbols that will be used in what could be used by modules, namely:

	iova_bitmap_alloc
	iova_bitmap_free
	iova_bitmap_for_each

Intel-SIG: 53f0b020218f vfio/iova_bitmap: Export more API symbols
Backport IOMMUFD Dirty Tracking

Link: https://lore.kernel.org/r/20231024135109.73787-2-joao.m.martins@oracle.com


Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
[ jz: amend commit log ]
Signed-off-by: Jason Zeng <jason.zeng@intel.com>