Input via TDM master unreliable due to low-level timing issues (xcore-200 only)

[xross]

xCORE as TDM master is currently unreliable due to low-level timing issues. This is experienced on input (record) only.

Attempts (clock shifting, swapping edges) to patch up timing on the XK-AUDIO-316-MC make XK-AUDIO-216-MC unreliable and vice versa. (https://github.com/xmos/lib_xua/blob/a1946f340ae9a175f46fa8299f1c3296a20d6af7/lib_xua/src/core/ports/audioports.xc#L87)

Hardware wise the boards are quite different with the 316 having much more sinks on the clock lines (4 DACs and 2 ADCs vs 1 ADC & 1 DAC). Ideally we can find some settings that operate well for all freqs and hardware.

Drive strength of the clock lines has already been increased for 316 but this is not possible on the 126