mac80211: remove the dependency on crypto_blkcipher

The only thing that using crypto_blkcipher with ecb does over just using
arc4 directly is wrapping the encrypt/decrypt function into a for loop,
looping over each individual character.
To be able to do this, it pulls in around 40 kb worth of unnecessary
kernel modules (at least on a MIPS embedded device).
Using arc4 directly not only eliminates those dependencies, it also makes
the code smaller.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/tkip.h b/net/mac80211/tkip.h
index 7e83dee..1cab9c8 100644
--- a/net/mac80211/tkip.h
+++ b/net/mac80211/tkip.h
@@ -15,7 +15,7 @@
 
 u8 *ieee80211_tkip_add_iv(u8 *pos, struct ieee80211_key *key, u16 iv16);
 
-int ieee80211_tkip_encrypt_data(struct crypto_blkcipher *tfm,
+int ieee80211_tkip_encrypt_data(struct crypto_cipher *tfm,
 				 struct ieee80211_key *key,
 				 u8 *pos, size_t payload_len, u8 *ta);
 enum {
@@ -24,7 +24,7 @@
 	TKIP_DECRYPT_INVALID_KEYIDX = -2,
 	TKIP_DECRYPT_REPLAY = -3,
 };
-int ieee80211_tkip_decrypt_data(struct crypto_blkcipher *tfm,
+int ieee80211_tkip_decrypt_data(struct crypto_cipher *tfm,
 				struct ieee80211_key *key,
 				u8 *payload, size_t payload_len, u8 *ta,
 				u8 *ra, int only_iv, int queue,