crypto: omap-aes - Fix CTR mode

Algo self tests are failing for CTR mode with omap-aes driver,
giving the following error:

[  150.053644]       omap_aes_crypt: request size is not exact amount of AES blocks
[  150.061262] alg: skcipher: encryption failed on test 5 for ctr-aes-omap: ret=22

This is because the input length is not aligned with AES_BLOCK_SIZE.
Adding support for omap-aes driver for inputs with length not aligned
with AES_BLOCK_SIZE.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>