Add support for reading boot files from FAT partition on BOOT1/GPP/SD in that order

Emummc config is read from boot partition, file based files still read from SD

Makefile

@@ -37,7 +37,7 @@ OBJS += $(addprefix $(BUILDDIR)/$(TARGET)/, \
 	fuse.o kfuse.o \
 	sdmmc.o sdmmc_driver.o emmc.o sd.o emummc.o \
 	bq24193.o max17050.o max7762x.o max77620-rtc.o \
-	hw_init.o \
+	hw_init.o boot_storage.o \
 )
 
 # Utilities.