Add iTPN Supports for Non-three channel image

[MGAMZ]

Motivation

The iTPN implementation does not support for Non-three channel image, while its neck is ready for it.
But I'm not sure if this change is in line with the original design.

Modification

Class iTPNHiViT: Pass other argments including channel arg to its superclass(HiViT).
Class MAEPretrainHead: Modify channels from 3 to self.in_channels, which allows users to specify specific channels number.

Use cases (Optional)

backbone=dict(type='iTPNHiViT', in_chans=1,),
neck=dict(type='iTPNPretrainDecoder', in_chans=1,),
head=dict(type='MAEPretrainHead', in_channels=1,),

[codecov]

Codecov Report

Patch coverage is 70.27% of modified lines.

❗ Current head 451df0a differs from pull request most recent head c8af8e0. Consider uploading reports for the commit c8af8e0 to get more accurate results

Files Changed	Coverage
configs/_base_/datasets/imagenet_bs128_mbv3.py	ø
configs/_base_/datasets/imagenet_bs32.py	ø
...onfigs/_base_/datasets/imagenet_bs32_pil_resize.py	ø
configs/_base_/datasets/imagenet_bs64_swin_224.py	ø
configs/_base_/datasets/imagenet_bs64_swin_384.py	ø
mmpretrain/apis/feature_extractor.py	0.00%
mmpretrain/apis/image_caption.py	0.00%
mmpretrain/apis/image_retrieval.py	0.00%
mmpretrain/apis/visual_grounding.py	0.00%
mmpretrain/apis/visual_question_answering.py	0.00%
... and 7 more

📢 Thoughts on this report? Let us know!.

[fangyixiao18]

please run pre-commit to fix lint problem