soundwire: bus: demote UNATTACHED state warnings to dev_dbg()

soundwire: bus: demote UNATTACHED state warnings to dev_dbg()

The dev_warn() messages in sdw_handle_slave_status() for UNATTACHED
transitions were added in commit d1b328557058 ("soundwire: bus: add
dev_warn() messages to track UNATTACHED devices") to debug attachment
failures with dynamic debug enabled.

These warnings fire during normal operation -- for example when a codec
driver triggers a hardware reset after firmware download, causing the
device to momentarily go UNATTACHED before re-attaching -- producing
misleading noise on every boot.

Demote the messages to dev_dbg() so they remain available via dynamic
debug for diagnosing real attachment failures without alarming users
during expected initialization sequences.

Fixes: d1b328557058 ("soundwire: bus: add dev_warn() messages to track UNATTACHED devices")
Signed-off-by: Cole Leavitt <cole@unwrap.rs>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20260218180210.9263-1-cole@unwrap.rs
Signed-off-by: Vinod Koul <vkoul@kernel.org>