Probe reports wanted from other Intel Xe machines (stage 2, read-only) #3

Stage 2 only reads registers. Reports from Tiger Lake, Alder Lake, Raptor Lake, Meteor Lake, Lunar Lake and Arc machines tell us what the shim sees elsewhere (BAR sizes, GMD_ID, stolen memory base, the firmware's pipe and GGTT state, PCH watchdog). How to run it and what to post: CONTRIBUTING.md, section Testing on your machine. Please do not run stage 4 yet.