driver core: allow kobj_to_dev() to take a const pointer

driver core: allow kobj_to_dev() to take a const pointer

If a const * to a kobject is passed to kobj_to_dev(), we want to return
back a const * to a device as the driver core shouldn't be modifying a
constant structure.  But when dealing with container_of() the pointer
const attribute is cast away, so we need to manually handle this by
determining the type of the pointer passed in to know the type of the
pointer to pass out.

Luckily _Generic can do this type of magic, and as the kernel now
supports C11 it is availble to us to handle this type of build-time type
detection.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221016104126.1259809-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>