qtnfmac: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Igor Mitsyanko <imitsyanko@quantenna.com>
Cc: Avinash Patil <avinashp@quantenna.com>
Cc: Sergey Matyukevich <smatyukevich@quantenna.com>
Cc: Kamlesh Rath <krath@quantenna.com>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>