crypto: caam - pair irq map and dispose in the same function

irq_dispose_mapping is not called on all error paths from caam_jr_init.
This takes care of several clean-up issues by performing resource
clean-up and allocation at the same level.

Signed-off-by: Cristian Stoica <cristian.stoica@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>