Add context save and restore for the System Control Module to suport
off-mode.

ETK and debobs definitions added by Peter De Schrijver.
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NPeter 'p2' De Schrijver <peter.de-schrijver@nokia.com>
Signed-off-by: NKevin Hilman <khilman@deeprootsystems.com>