software node: Constify node_group in registration functions

software node: Constify node_group in registration functions

The software_node_register_node_group() and
software_node_unregister_node_group() functions take in essence an
array of pointers to software_node structs. Since the functions do not
modify the array declare the argument as constant, so that static
arrays can be declared as const and annotated as __initconst.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: https://lore.kernel.org/r/2zny5grbgtwbplynxffxg6dkgjgqf45aigwmgxio5stesdr3wi@gf2zamk5amic
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>