nRF: PWMAudioOut: fix half-speed playback of stereo samples

The "spacing" of "buffer structure" is confusing, use the "channel count"
instead.

Testing performed on nrf52840 feather:

Play stereo and mono, 8- and 16-bit, 8kHz RawSamples representing 333.33Hz
square waves.

Use both mono and stereo PWMAudioOut instances.

Scope the RC-filtered signal and use the scope's frequency
measurement function, verify the frequency is 333 or 334Hz in all tested
cases.

In the "stereo output" cases, verify both the L and R channels.  Verify
the output amplitude is the same in both channels.

In the "stereo output" cases, run a second test where the L channel's
amplitude is attenuated 50%. Verify the output amplitude is correct
in each channel.

0 files changed, 0 insertions, 0 deletions