image-fit-sig: Remove padding check

image-fit-sig: Remove padding check

The padding algorithm is not mandatory for all signing algorithm.
For example, ECDSA does not require a padding method.

For RSA requiring PKCS padding, the belonging info->crypto(), assigned
with rsa_verify_key(), also has the check on the validity of info->padding().

Thus, remove the info->padding check from the upper, general layer.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Simon Glass <sjg@chromium.org>