i3c: master: svc: Flush FIFO before sending Dynamic Address Assignment(DAA)

i3c: master: svc: Flush FIFO before sending Dynamic Address Assignment(DAA)

[ Upstream commit a892ee4cf22a50e1d6988d0464a9a421f3e5db2f ]

Ensure the FIFO is empty before issuing the DAA command to prevent
incorrect command data from being sent. Align with other data transfers,
such as svc_i3c_master_start_xfer_locked(), which flushes the FIFO before
sending a command.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20250129162250.3629189-1-Frank.Li@nxp.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>