staging: ccree: rename vars/structs/enums from ssi_ to cc_

Unify naming convention by renaming all ssi_ vars/structs/enums
and variables to cc_*

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