hdmidongle: enable CAAM crypto processor

Amongst other things, the CAAM provides a fast hardware random number
generator. This is particularly useful here, as the kernel has few
entropy sources to draw on in this device otherwise, and random number
generation (eg. for crypto keys) is ridiculously slow (~8 bytes/30 sec
type slow).

The CAAM provides both /dev/crypto acceleration interface, and
/dev/hwrng random number source. To feed the kernel entropy pool,
install rngd from rng-tools, and then:

    rngd -r /dev/hwrng -o /dev/random

and you will never run out of good random numbers again :)