Actually, in that same board fiel, there are structures that are initialized to do that with the General Purpose EVM:
static u8 am335x_iis_serializer_direction1[] = { INACTIVE_MODE, INACTIVE_MODE, TX_MODE, RX_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, INACTIVE_MODE, }; static struct snd_platform_data am335x_evm_snd_data1 = { .tx_dma_offset = 0x46400000, /* McASP1 */ .rx_dma_offset = 0x46400000, .op_mode = DAVINCI_MCASP_IIS_MODE, .num_serializer = ARRAY_SIZE(am335x_iis_serializer_direction1), .tdm_slots = 2, .serial_dir = am335x_iis_serializer_direction1, .asp_chan_q = EVENTQ_2, .version = MCASP_VERSION_3, .txnumevt = 32, .rxnumevt = 32, .get_context_loss_count = omap_pm_get_dev_context_loss_count, };So you'd just have to reuse these configurations for the Starter Kit structures.
Josh