amazon/common-hdx: set rmrf flag on system

Change-Id: I1883b00fb605b6b336370bf49733760b8e3f94a2
amazon/common-hdx: custom build-fs for copying system data to rom-slot

Change-Id: Ib3c63e856633a090913b7cda4b779acd656a2fd0
amazon/common-hdx: update hijack

Change-Id: I0aa8e60f19cf316e24d781804a65336ed43932ce