[SYSDATA] Update Switchslot system compatible with RAUC
Changed memory structure of Switchslot and it management, included the slot switching machinism. Now a boot order list is used to select the slot from witch perform the boot. This behavior is similar to the RAUC's methodology. The upgrade includes:
- core business logic;
- u-boot command (sysdata);
- userspace tool (fw_sysdata).