You cannot. The P25 runs a RTOS based on Thread-X its compiled into a firmware load that's loaded directly to the client or though the client management software from Teradici. It's built and developed to run on the propritary chip design in the client.
Now, if you wanted to pull together a bunch of dev tools, build your on RTOS version of Linux port any missing hardware drivers to the hardware platform etc. create you own bootloader tools etc., etc. etc. technically anything is possible.
WP