crypto: crypto4xx - fix missing irq devname

crypto4xx_device's name variable is not set to anything.
The common devname for request_irq seems to be the module
name. This will fix the seemingly anonymous interrupt
entry in /proc/interrupts for crypto4xx.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>