crypto: s5p-sss - Fix completing crypto request in IRQ handler

crypto: s5p-sss - Fix completing crypto request in IRQ handler

In a regular interrupt handler driver was finishing the crypt/decrypt
request by calling complete on crypto request.  This is disallowed since
converting to skcipher in commit b286d8b1a690 ("crypto: skcipher - Add
skcipher walk interface") and causes a warning:
	WARNING: CPU: 0 PID: 0 at crypto/skcipher.c:430 skcipher_walk_first+0x13c/0x14c

The interrupt is marked shared but in fact there are no other users
sharing it.  Thus the simplest solution seems to be to just use a
threaded interrupt handler, after converting it to oneshot.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>