power_mgmt: Do not notify deep sleep if bootloader does context restore

Some bootloaders have power management support to restoer context
upon resume from deep sleep. In such cases, the OS startup code
should call the notification hook. Create Kconfig flags to configure
this option.

Jira: 1257
Change-Id: I9f40c5fa077c2f17dc8e9f11604c3ed17e549ed5
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>