driver core: bus: move lock_class_key into dynamic structure

driver core: bus: move lock_class_key into dynamic structure

Move the lock_class_key structure out of struct bus_type and into the
dynamic structure we create already for all bus_types registered with
the kernel.  This saves on static space and removes one more writable
field in struct bus_type.

In the future, the same field can be moved out of the struct class logic
because it shares this same private structure.

Most everyone will never notice this change, as lockdep is not enabled
in real systems so no memory or logic changes are happening for them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20230201083349.4038660-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>