Exosphere: Fix SE definition bug, misc other bugs. Now boots on 1.0.0

Use uintX_t for the SE & copy bugfixed SE struct definition

Exosphere: Fix extremely spooky Security Engine bugs, now makes it to the end of package2loader.

Integrate 5.x SMC API changes, add 4.x specific setup, implement target firmware selection

Implement half of bootup_misc_mmio()

Implement BootConfig.

Fix decrypt_data_into_keyslot

Clean up SE TODOs, implement GIC nonsecure init

Finish implementing Security Engine context save

Implement more SE context save functionality

Implement the rest of smcCpuSuspend with skeleton SE API calls.

Rewrite the memory map-related code... ...

...other style fixes, etc.

Move source files to src/, add Makefile, fix all build and linkage errors, etc.