mtmd: add MiMo v2.5 vision (#22883)
* mimo-v2.5: vision support
* mimo-v2.5: use fused qkv for vision
* mimi-v2.5: fix f16 vision overflow
* mimo-v2.5: comment cleanups
* mimo-v2.5: Flash doesn't have mmproj
more cleanup
remember to use filter_tensors
* mimo-v2.5: fix trailing whitespace
