exo/mariko fatal: save fatal error binaries to the SD

exosphere/mariko_fatal/source/fatal_sdmmc.hpp

@@ -21,5 +21,6 @@ namespace ams::secmon::fatal {
     Result InitializeSdCard();
     Result CheckSdCardConnection(sdmmc::SpeedMode *out_sm, sdmmc::BusWidth *out_bw);
     Result ReadSdCard(void *dst, size_t size, size_t sector_index, size_t sector_count);
+    Result WriteSdCard(size_t sector_index, size_t sector_count, const void *src, size_t size);
 
 }