setup-makefiles: Fix typo

Change-Id: I7c8dbd424053e32745330a93171a3291698855c8
Make gpe-boot.img and include as system/gpe-boot.img for install

Also add PHONY targets for make gpe-bootimage and gpe-recoveryimage
Retail versions use f2fs for data partion and GPE uses EXT4

Change-Id: Ib1e94c28d5369fb01ef57135211925f553b2d2dd