domctl: introduce a macro to set the grant table max version

domctl: introduce a macro to set the grant table max version

Such macro just clamps the passed version to fit in the designated
bits of the domctl field. The main purpose is to make it clearer in
the code when max grant version is being set in the grant_opts field.

Existing users that where setting the version in the grant_opts field
are switched to use the macro.

No functional change intended.

Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Ian Jackson <iwj@xenproject.org>
Release-Acked-by: Ian Jackson <iwj@xenproject.org>