BACKPORT: usb: roles: add lockdep class key to struct usb_role_switch

There can be multiple role switch devices running on a platform. Given
that lockdep is not capable of differentiating between locks of
different instances, false positive warnings for circular locking are
reported. To prevent this, register unique lockdep key for each of the
individual instances.

Change-Id: I087906873262e6c5c7425d02d4281c8ab1b01809
Signed-off-by: Amit Sunil Dhamne <amitsd@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Link: https://lore.kernel.org/r/20240822223717.253433-1-amitsd@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bug: 357676850
(cherry picked from commit fc88bb11)
[ bvanassche: included if (IS_ERR_OR_NULL(sw)) inversion ]
Signed-off-by: Bart Van Assche <bvanassche@acm.org>