Support for booting from eMMC

Fusee will Look for FAT32 partition on BOOT1 (1MB offset), BOOT1, GPP, SD, in this order
If a .no_boot_storage file is found in the root directory, the partition is skipped

fusee/program/source/fusee_mmc.hpp

@@ -19,6 +19,7 @@
 namespace ams::nxboot {
 
     Result InitializeMmc();
+    void FinalizeMmc();
     Result CheckMmcConnection(sdmmc::SpeedMode *out_sm, sdmmc::BusWidth *out_bw);
     Result GetMmcMemoryCapacity(u32 *out_num_sectors, sdmmc::MmcPartition partition);