crypto: safexcel - Raise firmware load failure message to error

At the moment if there is no firmware available for the safexcel driver
it will fail to load with a cryptic:

crypto-safexcel f2800000.crypto: TRC init: 15360d,80a (48r,256h)
crypto-safexcel f2800000.crypto: HW init failed (-2)

Raise the logging level of the firmware load failure to err rather than
dbg so that it's obvious what the reason for the HW init failure is.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>