Exosphere: Fix bugs, now boots 5.1.0 successfully.

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

Exosphere: Fix MC carveout setup bug, now receives smcCpuOn from kernel on 1.0.0.

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

Fix async expMod output + smcUnwrapAesWrappedTitlekey

Fix fuse_get_hardware_type for 4.x

Add debug region to mapped memory

Fix smcConfigureCarveout

Make enum names consistent

Fix lock_try_acquire(&g_is_user_smc_in_progress) calls

Fix lock clear in warmboot_main

Implement critical section (Lamport's Baker s algorithm)... ...

thanks @fincs for sample code

Status callback keys have guaranteed atomicity from caller locks.

Implement Panic() stub.

Skeleton smcCpuOff, fix building, fix smcConfigureCarveout

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

...other style fixes, etc.

Start implementing smcCpuSuspend

all: Make file-scope variables internally linked where applicable (#57) ...

Narrows the scope of visible symbols to where they're actually used. Also
makes it easier to see true globals in source files
(ones used from multiple translation units)

lock: Use stdatomic.h (#56) ...

Provides the same assembly output while using the standardized interface

e.g.

0000000000000000 <set_priv_smc_in_progress>:
   0:   90000000    adrp    x0, 0 <set_priv_smc_in_progress>
   4:   91000000    add x0, x0, #0x0
   8:   52800022    mov w2, #0x1                    // #1
   c:   d503201f    nop
  10:   085ffc01    ldaxrb  w1, [x0]
  14:   08037c02    stxrb   w3, w2, [x0]
  18:   35ffffc3    cbnz    w3, 10 <set_priv_smc_in_progress+0x10>
  1c:   72001c3f    tst w1, #0xff
  20:   54ffff81    b.ne    10 <set_priv_smc_in_progress+0x10>  // b.any
  24:   d65f03c0    ret

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