[PATCHv2.1] dw_dmac: make usage of dw_dma_slave optional

The driver requires a custom slave configuration to be present to be able to make the slave transfers. Nevertheless, in some cases we need only the request line as an additional information to the generic slave configuration. The request line is provided by slave_id parameter of the

[PATCHv2.1] dw_dmac: make usage of dw_dma_slave optional

The driver requires a custom slave configuration to be present to be able to make the slave transfers. Nevertheless, in some cases we need only the request line as an additional information to the generic slave configuration. The request line is provided by slave_id parameter of the