This PR adds a method for the application programmer to change the default SPI interface used by the HAL layer.
In order not to interfere with existing source code it defaults to SPI (same as the currently hard coded SPI interface) and by using the hal_set_spi() method the programmer can now change the used SPI interface. This must be called before os_init().
This PR adds a method for the application programmer to change the default SPI interface used by the HAL layer. In order not to interfere with existing source code it defaults to SPI (same as the currently hard coded SPI interface) and by using the hal_set_spi() method the programmer can now change the used SPI interface. This must be called before os_init().