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_boot_storage.hpp

@@ -0,0 +1,19 @@
+#include <exosphere.hpp>
+
+namespace ams::nxboot {
+	enum BootStorage : u32 {
+		BootDrive_Min      = 0,
+		BootDrive_Boot1Off = 0,
+		BootDrive_Boot1,
+		BootDrive_System,
+		BootDrive_SD,
+		BootDrive_Max,
+		BootDrive_Invalid = BootDrive_Max,
+	};
+
+
+	Result MountBootStorage();
+	void FinalizeBootStorage();
+	void UnmountBootStorage();
+	BootStorage GetBootStorage();
+}