driver core: class: fix documentation for class_create()

In commit dcfbb67e ("driver core: class: use lock_class_key already
present in struct subsys_private") we removed the key parameter to the
function class_create() but forgot to remove it from the kerneldoc,
which causes a build warning.  Fix that up by removing the key parameter
from the documentation as it is now gone.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: dcfbb67e ("driver core: class: use lock_class_key already present in struct subsys_private")
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20230327081828.1087364-1-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>