User mode may now access the read, write, and trigger APIs.
Unlike supervisor mode, memory slabs are not dealt with directly,
the data is always copied.
A new driver API added to fetch the current channel configuration,
used by the system call handlers.
The i2s_sam_ssc driver updated for the new API. CAVS driver not
modified as there is no user mode port to Xtensa yet.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Andrew Boie