SPI baudrate hardcoded, should use existing frequency from SPI object

[kattni]

This is the same issue as adafruit/Adafruit_CircuitPython_TLC59711#8.

Problematic code is here:

Adafruit_CircuitPython_TLC5947/adafruit_tlc5947.py

Line 161 in 60d3653

self._spi.configure(baudrate=1000000, polarity=0, phase=0, bits=8)

@FoamyGuy Are you up for fixing this like you did the other TLC lib?

[FoamyGuy]

Yep I can handle it in this library as well.

[tannewt]

I think it'd be better to remove the configure all-together if we are assuming the SPI is set up appropriately outside of the driver.