soundwire: cadence: add BTP support for DP0

soundwire: cadence: add BTP support for DP0

The register definitions are missing a BULK_ENABLE bitfield which must
be set for DP0.

In addition, the existing mapping from PDI to Data Port is 1:1. That's
fine for PCM streams which are by construction in one direction
only. The BTP/BRA protocol is bidirectional and relies on DP0 only,
which breaks the 1:1 mapping. DP0 MUST be mapped to both PDI0 and
PDI1, with PDI0 taking care of the TX direction and PDI1 of the RX
direction.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.dev>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Tested-by: shumingf@realtek.com
Link: https://lore.kernel.org/r/20250227140615.8147-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>