net: rtlwifi: Remove void* casts related to delayed work

INIT_DELAYED_WORK() takes two arguments: A pointer to the delayed work and
a function reference for the callback.

The rtl code casts all function references to (void *) because the
callbacks in use are not matching the required function signature. That's
error prone and bad pratice.

Some of the callback functions are also global, but only used in a single
file.

Clean the mess up by:

  - Adding the proper arguments to the callback functions and using them in
    the container_of() constructs correctly which removes the hideous
    container_of_dwork_rtl() macro as well.

  - Removing the type cast at the initializers

  - Making the unnecessary global functions static

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>