staging: rtl8723bs: remove unused code

Remove commented rtw_is_cckrates_included() and
rtw_is_cckratesonly_included() from os_dep/ioctl_linux.c.
Both are defined in core/rtw_ieee80211.c.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>