panfrost: Abstract kernel driver operations
What does this MR do and why?
This MR adds an abstraction layer for KMD (kernel mode driver) operations so we can prepare for the addition of a new kernel driver for CSF hardware (panthor).
Note that we only add a backend for the panfrost kernel driver, the panthor backend will be added in a separate MR, along with all other patches allowing us to support v10 HW.
Based on !26356 (merged)
/cc @kusma @nanokatze