thermosphere: major refactor of memory map

- use recursive stage 1 page table (thanks @fincs for this idea)
- NULL now unmapped
- no identity mapping
- image + GICv2 now mapped at the same address for every platform
- tempbss mapped just after "real" bss, can now steal unused mem from
the latter
- no hardcoded VAs for other MMIO devices
- tegra: remove timers, use the generic timer instead

thermosphere/src/utils.c

@@ -62,7 +62,7 @@ bool writeEl1Memory(uintptr_t addr, const void *src, size_t size)
     memcpy((void *)pa, src, size);
     cacheHandleSelfModifyingCodePoU((const void *)pa, size);
 
-    __tlb_invalidate_el1_stage12(); //FIXME FIXME FIXME
+    __tlb_invalidate_el1_stage12_local(); //FIXME FIXME FIXME
     __dsb_sy();
     __isb();