Introduce PcdXenGrantFrames to replace a define in XenBusDxe and allow the same value to be used in a different module. The reason for the number of page to be 4 doesn't exist anymore, so simply remove the comment. Signed-off-by: Anthony PERARD <anthony.perard@citrix.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Message-Id: <20190813113119.14804-33-anthony.perard@citrix.com>