[janus] Fix failing tests on mi3XX (#38426)
* Fix multiple devices error on Janus
* Fix AttributeError on Janus BOI token
* Initialize lm first in Janus to get correct device map
* Added expectations for Janus test_model_generate_images
* Fixed JanusVisionEncoderLayer being split across devices
* Code formatting
* Adding modeling file
* Reverted changes out of scope for this PR
