sst: tweak the shared functions so we don't crash the ASoC driver

The ASoC driver is currently pulling bits from staging rather than its own
copy. Post all the merges and fixes we've put back an assumption that
crashes ASoC so we need to fix it differently.

(See 0ed625b2)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>