crypto: caam - fix RNG state handle instantiation descriptor

The way the DECO runs a descriptor through the direct (debug)
interface is different from the JRI interface: the DECO will
continue to try and execute the next commands, after the descriptor
buffer has ended. This leads to unpredictable results and possibly
to locking up of the DECO. This patch adds a halt command at the
end of the descriptor to ensure the DECO halts when it reaches
the end of the descriptor buffer.

Signed-off-by: Alex Porosanu <alexandru.porosanu@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>