crypto: crypto4xx - add aes-ctr support

This patch adds support for the aes-ctr skcipher.

name         : ctr(aes)
driver       : ctr-aes-ppc4xx
module       : crypto4xx
priority     : 300
refcnt       : 1
selftest     : passed
internal     : no
type         : skcipher
async        : yes
blocksize    : 16
min keysize  : 16
max keysize  : 32
ivsize       : 16
chunksize    : 16
walksize     : 16

The hardware uses only the last 32-bits as the counter while the
kernel tests (aes_ctr_enc_tv_template[4] for example) expect that
the whole IV is a counter. To make this work, the driver will
fallback if the counter is going to overlow.

The aead's crypto4xx_setup_fallback() function is renamed to
crypto4xx_aead_setup_fallback.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 3dbc475..1fa263a 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -302,6 +302,7 @@
 	select CRYPTO_AEAD
 	select CRYPTO_AES
 	select CRYPTO_CCM
+	select CRYPTO_CTR
 	select CRYPTO_GCM
 	select CRYPTO_BLKCIPHER
 	help