crypto: sun8i-ss - avoid hash and rng references

crypto: sun8i-ss - avoid hash and rng references

While the sun4i-ss and sun8i-ce drivers started selecting CRYPTO_RNG,
the sun8i-ss variant does not, and causes a link failure:

aarch64-linux-ld: drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.o: in function `sun8i_ss_unregister_algs':
sun8i-ss-core.c:(.text.sun8i_ss_unregister_algs+0x94): undefined reference to `crypto_unregister_rng'
aarch64-linux-ld: drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.o: in function `sun8i_ss_probe':
sun8i-ss-core.c:(.text.sun8i_ss_probe+0x40c): undefined reference to `crypto_register_rng'

Looking more closely, I see that all of the allwinner crypto drivers have the
same logic where the rng and hash parts of the driver are optional, but then the
generic code is still selected, which is a bit inconsistent, aside from the
missing CRYPTO_RNG select on sun8i-ss.

Change the approach so only the bits that are actually used are built, using
ifdef checks around the optional portions that match the optional references
to the sub-drivers.

Ideally the drivers would get reworked in a way that keeps all the bits
related to the skcipher/ahash/rng codecs in the respective sub-drivers,
rather than having a common driver that knows about all of these.

Fixes: cdadc1435937 ("crypto: cryptomgr - Select algorithm types only when CRYPTO_SELFTESTS")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>