soundwire: bus: Remove now outdated comments on no_pm IO

Things have moved more towards end drivers using the no_pm versions of
the IO functions. See commits:

commit 167790ab ("soundwire: export sdw_write/read_no_pm functions")
commit 62dc9f3f ("soundwire: bus: export sdw_nwrite_no_pm and
                      sdw_nread_no_pm functions")

As such this comment is now misleading, so remove it.
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230322164948.566962-1-ckeepax@opensource.cirrus.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/soundwire/bus.c

@@ -384,9 +384,6 @@ int sdw_fill_msg(struct sdw_msg *msg, struct sdw_slave *slave,
 
 /*
  * Read/Write IO functions.
- * no_pm versions can only be called by the bus, e.g. while enumerating or
- * handling suspend-resume sequences.
- * all clients need to use the pm versions
  */
 
 int sdw_nread_no_pm(struct sdw_slave *slave, u32 addr, size_t count, u8 *val)