staging: rtl8723bs: remove cckrates{only}_included()

staging: rtl8723bs: remove cckrates{only}_included()

In rtw_ieee80211.c there are rtw_is_cckrates_included() and
rtw_is_cckratesonly_included() which have the same functionality as
cckrates_included() and cckrates_only_included() defined in
rtw_wlan_util.c. Remove the functions from rtw_wlan_util.c and use
those from rtw_ieee80211.c. Remove the now unused variable ratelen.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200913162206.19477-1-straube.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>