[Blackfin] arch: set_bfin_dma_config shouldnt set SYNC or RESTART by default -...

[Blackfin] arch: set_bfin_dma_config shouldnt set SYNC or RESTART by default - add argument or option

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>