crypto: dcp - Use devm_request_irq()

Using Use devm_request_irq() can make the code smaller and simpler, as we do
not need to call free_irq() in the probe error path and in the remove function.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>