Small ldm3d fix (#7464)
* fixed typo
* updated doc to be consistent in naming
* make style/quality
* preprocessing for 4 channels and not 6
* make style
* test for 4c
* make style/quality
* fixed test on cpu
* fixed doc typo
* changed default ckpt to 4c
* Update pipeline_stable_diffusion_ldm3d.py
* fix bug
---------
Co-authored-by: Aflalo <estellea@isl-iam1.rr.intel.com>
Co-authored-by: Aflalo <estellea@isl-gpu33.rr.intel.com>
Co-authored-by: Aflalo <estellea@isl-gpu38.rr.intel.com>
