Routine rtl_addr_delay() uses delay statements in code that can
sleep. To improve system responsiveness, the various delay statements
are changed.

In addition, routines rtl_rfreg_delay() and rtl_bb_delay() are
rewritten to use the code in rtl_addr_delay() for most of their
input values.
Suggested-by: NByeoungwook Kim <quddnr145@gmail.com>
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>