init_falcon: Add props for falcon_gpe

Use install time script to determine if gpe-boot.img needs to be
installed.

Change-Id: I9fc2b3fa2a9f9d1a78a10ed6a4d13a6dacfe85f0
Revert install gpe-bootimg in favor of fstab swap at boot

Change-Id: Ie6701d3606ed017c4a8c03a5d40fd73c23655c0e