crypto: picoxcell - Remove spacc_is_compatible() wrapper function

The function is used to check either the platform device ID name or the OF
node's compatible (depending how the device was registered) to know which
device type was registered.

But the driver is for a DT-only platform and so there's no need for this
level of indirection since the devices can only be registered via OF.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>