crypto: stm32 - Fix sparse warnings

This patch fixes most of the sparse endianness warnings in stm32.
The patch itself doesn't change anything apart from markings,
but there is some questionable code in stm32_cryp_check_ctr_counter.

That function operates on the counters as if they're in CPU order,
however, they're then written out as big-endian.  This looks like
a genuine bug.  Therefore I've left that warning alone until
someone can confirm that this really does work as intended on
little-endian.

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