sandbox: Remove OF_HOSTFILE

OF_HOSTFILE is used on sandbox configs only.  Although it's pretty
unique and not causing any confusions,  we are better of having simpler
config options for the DTB.

So let's replace that with the existing OF_BOARD.  U-Boot would then
have only three config options for the DTB origin.
- OF_SEPARATE, build separately from U-Boot
- OF_BOARD, board specific way of providing the DTB
- OF_EMBED embedded in the u-boot binary(should not be used in production

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/armltd/vexpress64/vexpress64.c b/board/armltd/vexpress64/vexpress64.c
index 2e42602..d2f307c 100644
--- a/board/armltd/vexpress64/vexpress64.c
+++ b/board/armltd/vexpress64/vexpress64.c
@@ -131,12 +131,15 @@
 	return ~0;
 }
 
-void *board_fdt_blob_setup(void)
+void *board_fdt_blob_setup(int *err)
 {
 	phys_addr_t fdt_rom_addr = find_dtb_in_nor_flash(CONFIG_JUNO_DTB_PART);
 
-	if (fdt_rom_addr == ~0UL)
+	*err = 0;
+	if (fdt_rom_addr == ~0UL) {
+		*err = -ENXIO;
 		return NULL;
+	}
 
 	return (void *)fdt_rom_addr;
 }