- Add support for variable width I2S (via XUA_I2S_N_BITS)
- Add support for variable width TDM (again via XUD_I2S_N_BITS when XUA_PCM_FORMAT=XUA_PCM_FORMAT_TDM)
- Includes support for xcore as I2S/TDM master and slave
- Add testing of the the above to test_i2s_loopback
- Rationalised test config building in test_i2s_loopback
- Documentation updated