staging: rtl8188eu: 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.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200929062847.23985-6-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>