Update MDAPI Checks for xe Kernel Driver

[bashbaug]

Description of Changes

Adds updates for the new xe kernel driver used by Lunar Lake and Battlemage GPUs. Specifically:

• Adds checks for MDAPI permissions for the xe kernel driver in addition to the previous i915 kernel driver.
• Tries to initialize MDAPI even if the MDAPI permission checks fail, to handle the case where there are multiple GPUs and sufficient permissions are set for the GPU used to collect metrics.
• Updates documentation to cover both kernel drivers.

Also, changes non-error output from cliloader to go to stdout rather than stderr. This makes it easier to page through output using utilities like more and less.

Testing Done

Tested on a machine with an Alder Lake iGPU using the i915 kernel driver and a Battlemage dGPU using the xe kernel driver. Verified that both permission checks are properly performed.