soundwire: bus: remove use of __func__ in dev_dbg

soundwire: bus: remove use of __func__ in dev_dbg

The module and function information can be added with
'modprobe foo dyndbg=+pmf'

Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20220823050158.2671245-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>