CONFIG_VFIO_AP is not available for thedefaultarchitecture x86.
Result is shown for architecture s390

VFIO support for AP devices

modulename: vfio_ap.ko

configname: CONFIG_VFIO_AP

Linux Kernel Configuration
└─>I/O subsystem
└─>VFIO support for AP devices
In linux kernel since version 3.10 (release Date: 2013-06-30)  
This driver grants access to Adjunct Processor (AP) devices
via the VFIO mediated device interface.

To compile this driver as a module, choose M here: the module
will be called vfio_ap.

source code: