mcu/fe310: Adjust mcu to api changes in bus driver
mcu/fe310: Adjust mcu to api changes in bus driver

Argument change in function bus_spi_hal_dev_create() for asynchronous
spi handling.

This simply changes old type of argument to new one.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core