staging: rtl8192u: rename CONFIG_IEEE80211_CRYPT_TKIP

The Kconfig symbol IEEE80211_CRYPT_TKIP was renamed to
LIB80211_CRYPT_TKIP in commit 274bfb8d ("lib80211: absorb crypto
bits from net/ieee80211"). So when rtl8192u was added as a staging
driver in v2.6.33 its checks for CONFIG_IEEE80211_CRYPT_TKIP were
already outdated. Use CONFIG_LIB80211_CRYPT_TKIP instead, as was clearly
intended.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>