CONFIG_AMD_PTDMA is not available for thedefaultarchitecture x86.
Result is shown for architecture 64BIT

AMD PassThru DMA Engine

modulename: ptdma.ko

configname: CONFIG_AMD_PTDMA

Linux Kernel Configuration
└─>Device Drivers
└─>DMA Engine support
└─>PCI support
└─>AMD PassThru DMA Engine
In linux kernel since version 5.2 (release Date: 2019-07-07)  
Enable support for the AMD PTDMA controller. This controller
provides DMA capabilities to perform high bandwidth memory to
memory and IO copy operations. It performs DMA transfer through
queue-based descriptor management. This DMA controller is intended
to be used with AMD Non-Transparent Bridge devices and not for
general purpose peripheral DMA.

source code: