tested on metro m7 (green prototype version) with max98357a i2s amplifier and the following test code:
```py
import board
import time
import digitalio
from audiobusio import I2SOut
from audiocore import RawSample
from microcontroller import pin
from ulab import numpy as np
n = np.array(np.sin(np.linspace(0, np.pi*2, 218, endpoint=False)) * 200, dtype=np.int16)
print(n)
r = RawSample(n, sample_rate=8000, channel_count=2)
def main():
with digitalio.DigitalInOut(board.LED) as l:
l.switch_to_output(True)
value = False
while True:
with I2SOut(pin.GPIO_06, pin.GPIO_07, pin.GPIO_04) as i:
time.sleep(.01)
l.value = value = not value
i.play(r, loop=True)
print(i.playing)
time.sleep(.5)
i.stop()
print("STOPPED")
print(i.playing)
time.sleep(.5)
i.play(r, loop=True)
print(i.playing)
print("PLAY AGAIN")
time.sleep(.5)
time.sleep(1)
```
Only stereo, 16-bit, raw samples were tested; the sample rate is actually fixed
at 48kHz in the core right now. There is more to do, but the basics work.
# Conflicts:
# ports/mimxrt10xx/Makefile
# ports/mimxrt10xx/mpconfigport.mk
This also removes the need to pin share because we don't use the
status LED while user code is running.
The status flashes fallback to the HW_STATUS LED if no RGB LED is
present. Each status has a unique blink pattern as well.
One caveat is the REPL state. In order to not pin share, we set the
RGB color once. PWM and single color will be shutoff immediately but
DotStars and NeoPixels will hold the color until the user overrides
it.
Fixes#4133
