Refactor fusee's makefile

Fix mmc->allow_voltage_switching assignment in sdmmc_init

Copy latest sdmmc driver to stage2

fusee: work around some dual-init SDMMC issues

Stage1: fix SE issue too

Use uintX_t for the SE & copy bugfixed SE struct definition

Stage1: fix potential alignment issue

fusee: improve SDR104 frequency and support AUTOCMD23

Stage2: Add exception handlers

Fix stack overflow when chainloading stage2

Fix exception handlers (thanks @fincs)

[stage1] Add exception handlers... which somehow don't work?

Fusee use CAR reboot for fatal errors

Remove packed when not needed

wtf pmc reboot doesn't fully work -- display doesn't reinitialize

Introduce fatal_error

fusee: correct computation of tuning block size

fusee: begin adding support for MMC HS modes

fusee: SD: implement tuning, allowing for all SD UHS-I speed

fusee: SD driver: implement everything necessary for UHS except tuning

fusee: correct constants in CAR

fusee: handle SDMMC speeds sanely

Add custom panic driver

Make struct tegra_pmc not packed

Actually don't use memcpy in sdmmc

Sync sdmmc changes between stage1 and 2

Revamp all the Makefiles (thanks @fincs @WinterMute) ...

... dependencies are now properly handled (e.g. header changes, etc.)

fusee sdmmc: don't time out on long reads

Fix tsec.c (thanks @rajkosto @tslater2006), fixes #106

Fix strncpy bugs in fusée, etc.