crypto: omap-aes - reject invalid input sizes for block modes

Block modes such as ECB and CBC only support input sizes that are
a round multiple of the block size, so align with the generic code
which returns -EINVAL when encountering inputs that violate this
rule.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Tero Kristo <t-kristo@ti.com>
Tested-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>