dmaengine: tegra20-apb: stop checking config->slave_id

Nothing sets the slave_id field any more, so stop accessing
it to allow the removal of this field.

Signed-off-by: Arnd Bergmann <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/tegra20-apb-dma.c

···
 	}
 
 	memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
-	if (tdc->slave_id == TEGRA_APBDMA_SLAVE_ID_INVALID &&
-	    sconfig->device_fc) {
-		if (sconfig->slave_id > TEGRA_APBDMA_CSR_REQ_SEL_MASK)
-			return -EINVAL;
-		tdc->slave_id = sconfig->slave_id;
-	}
 	tdc->config_init = true;
 
 	return 0;