modified code for using ROCm backened within the PyTorch framework

[xiabo123]

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Motivation

Related issue: #1949 #2035
This PR enables HIP as a backened for pytorch only.

Modification

1. Added './mmcv/ops/csrc/pytorch' to the include directory as hipify in pytorch needed to hipify 'spconv_utils.h'.
2. rocblas has ambiguities for 'is_complex' ultimately from the order of the include-files in some files. The workaround in this PR is to add '#include spconv_utils.h' before the other file to break this ambiguity. This may go against the style guideline, unfortunately. Albeit, this issue has been reported and will be addressed with future versions of ROCm.
3. Added __shfl_down without mask in ./mmcv/ops/common/cuda/correlation_cuda.cuh since HIP does not have warp level granularity yet. The test in ./tests/test_ops/test_correlation.py passed.

BC-breaking (Optional)

N/A

Use cases (Optional)

Using MMCV with the pytorch framework on AMD GPUs.

Checklist

Before PR:

• I have read and followed the workflow indicated in the CONTRIBUTING.md to create this PR.
• Pre-commit or linting tools indicated in CONTRIBUTING.md are used to fix the potential lint issues.
• Bug fixes are covered by unit tests, the case that causes the bug should be added in the unit tests.
• New functionalities are covered by complete unit tests. If not, please add more unit test to ensure the correctness.
• The documentation has been modified accordingly, including docstring or example tutorials.

After PR:

• If the modification has potential influence on downstream or other related projects, this PR should be tested with some of those projects, like MMDet or MMCls.
• CLA has been signed and all committers have signed the CLA in this PR.

[CLAassistant]

All committers have signed the CLA.

[zhouzaida]

closed by #1918