As part of the simplification/cleanup of the iaa statistics, remove
the comp/decomp delay statistics.

They're actually not really useful and can be/are being more flexibly
generated using standard kernel tracing infrastructure.
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>