NOTE: This work is not yet fully complete; kernel is done, but
it was taking an exceedingly long time to get through libstratosphere.
Thus, I've temporarily added -Wno-error=unused-result for libstratosphere/stratosphere.

All warnings should be fixed to do the same thing Nintendo does as relevant, but this
is taking a phenomenally long time and is not actually the most important work to do,
so it can be put off for some time to prioritize other tasks for 21.0.0 support.

* sdmmc: begin skeletoning sdmmc driver

* sdmmc: add most of SdHostStandardController

* sdmmc: implement most of SdmmcController

* sdmmc: Sdmmc2Controller

* sdmmc: skeleton implementation of Sdmmc1Controller

* sdmmc: complete abstract logic for Sdmmc1 power controller

* sdmmc: implement gpio handling for sdmmc1-register-control

* sdmmc: implement pinmux handling for sdmmc1-register-control

* sdmmc: fix building for arm32 and in stratosphere context

* sdmmc: implement voltage enable/set for sdmmc1-register-control

* util: move T(V)SNPrintf from kernel to util

* sdmmc: implement BaseDeviceAccessor

* sdmmc: implement MmcDeviceAccessor

* sdmmc: implement clock reset controller for register api

* sdmmc: fix bug in WaitWhileCommandInhibit, add mmc accessors

* exo: add sdmmc test program

* sdmmc: fix speed mode extension, add CheckMmcConnection for debug

* sdmmc: add DeviceDetector, gpio: implement client api

* gpio: modernize client api instead of doing it the lazy way

* sdmmc: SdCardDeviceAccessor impl

* sdmmc: update test program to read first two sectors of sd card

* sdmmc: fix vref sel

* sdmmc: finish outward-facing api (untested)

* ams: changes for libvapours including tegra register defs

* sdmmc: remove hwinit