Convert kselftest lib suite to kunit

[musamaanjum]

#414 has details why this is required.

[musamaanjum]

Sent series to convert bitmap.sh and lib/test_bitmap.c to kunit:

[PATCH 0/3] bitmap: Convert test_bitmap to kunit test
[PATCH 1/3] bitmap: convert test_bitmap to KUnit test
[PATCH 2/3] bitmap: Rename module
[PATCH 3/3] selftests: lib: remove test_bitmap

[musamaanjum]

From discussion, it was evident that the maintainer doesn't agree as you'll need KUNIT config enabled to run the test if conversion is made. Maybe we need more improvements to the KUNIT side before this kind of conversion.