staging: ccree: fix AEAD func naming convention

The aead files was using a func naming convention which was inconsistent
(ssi vs. cc), included a useless prefix (ssi_aead) and often used
too long function names producing monster func names such as
ssi_aead_gcm_setup_ghash_desc() that made the call site code hard
to read.

Make the code more readable by switching to a simpler, consistent naming
conventionfor all the function defined in the file.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>