doc: add IOVA aware API changes in release notes

The wording changes have been done in the API without breaking
the ABI. The deprecated fields and symbols can be removed later
when an another ABI change will be required.
The deprecation notice can be removed.

The release notes describe the new available API with IOVA wording.

Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Santosh Shukla <santosh.shukla@caviumnetworks.com>
Acked-by: John McNamara <john.mcnamara@intel.com>