dmaengine: cppi41: add missing bitfields

Add missing directions, residue_granularity,
srd_addr_widths and dst_addr_widths bitfields.

Without those we will see a kernel WARN()
when loading musb on am335x devices.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>