CTL_SPI_BUS_t *platform_private_spi_bus_instance[];
platform_private_spi_bus_instance contains the recoded instances of platform SPI buses, indexed using the platform SPI bus index. When an SPI bus is correctly configured by platform_configure_spi_bus, the SPI bus instance is written to platform_private_spi_bus_instance so that platform_spi_bus can access and return an appropriate SPI bus.