driver core: class: make namespace and get_ownership take const *

The callbacks in struct class namespace() and get_ownership() do not
modify the struct device passed to them, so mark the pointer as constant
and fix up all callbacks in the kernel to have the correct function
signature.

This helps make it more obvious what calls and callbacks do, and do not,
modify structures passed to them.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221001165426.2690912-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>