avr32: at32ap700x: Specify DMA Flow Controller, Src and Dst msize

Now that the dw_dmac DMA driver supports configurable Flow Controller, source
and destination burst or msize, we need to specify which ones to use. Msize or
burst size was previously hardcoded to 1, Flow controller was DMA for both
M2P & P2M transfers.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>