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/arch/arm/mach-stm32mp/boot_params.c b/arch/arm/mach-stm32mp/boot_params.c
index 84647e7..e91ef1b 100644
--- a/arch/arm/mach-stm32mp/boot_params.c
+++ b/arch/arm/mach-stm32mp/boot_params.c
@@ -33,10 +33,11 @@
  * Use the saved FDT address provided by TF-A at boot time (NT_FW_CONFIG =
  * Non Trusted Firmware configuration file) when the pointer is valid
  */
-void *board_fdt_blob_setup(void)
+void *board_fdt_blob_setup(int *err)
 {
 	log_debug("%s: nt_fw_dtb=%lx\n", __func__, nt_fw_dtb);
 
+	*err = 0;
 	/* use external device tree only if address is valid */
 	if (nt_fw_dtb >= STM32_DDR_BASE) {
 		if (fdt_magic(nt_fw_dtb) == FDT_MAGIC)
diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
index 48636ab..9887d09 100644
--- a/arch/sandbox/cpu/cpu.c
+++ b/arch/sandbox/cpu/cpu.c
@@ -291,44 +291,51 @@
 {
 }
 
-int sandbox_read_fdt_from_file(void)
+void *board_fdt_blob_setup(int *ret)
 {
 	struct sandbox_state *state = state_get_current();
 	const char *fname = state->fdt_fname;
-	void *blob;
+	void *blob = NULL;
 	loff_t size;
 	int err;
 	int fd;
 
 	blob = map_sysmem(CONFIG_SYS_FDT_LOAD_ADDR, 0);
+	*ret = 0;
 	if (!state->fdt_fname) {
 		err = fdt_create_empty_tree(blob, 256);
 		if (!err)
 			goto done;
 		printf("Unable to create empty FDT: %s\n", fdt_strerror(err));
-		return -EINVAL;
+		*ret = -EINVAL;
+		goto fail;
 	}
 
 	err = os_get_filesize(fname, &size);
 	if (err < 0) {
-		printf("Failed to file FDT file '%s'\n", fname);
-		return err;
+		printf("Failed to find FDT file '%s'\n", fname);
+		*ret = err;
+		goto fail;
 	}
 	fd = os_open(fname, OS_O_RDONLY);
 	if (fd < 0) {
 		printf("Failed to open FDT file '%s'\n", fname);
-		return -EACCES;
+		*ret = -EACCES;
+		goto fail;
 	}
+
 	if (os_read(fd, blob, size) != size) {
 		os_close(fd);
-		return -EIO;
+		printf("Failed to read FDT file '%s'\n", fname);
+		*ret =  -EIO;
+		goto fail;
 	}
 	os_close(fd);
 
 done:
-	gd->fdt_blob = blob;
-
-	return 0;
+	return blob;
+fail:
+	return NULL;
 }
 
 ulong timer_get_boot_us(void)
diff --git a/arch/sandbox/include/asm/u-boot-sandbox.h b/arch/sandbox/include/asm/u-boot-sandbox.h
index 73b1897..56dc13c 100644
--- a/arch/sandbox/include/asm/u-boot-sandbox.h
+++ b/arch/sandbox/include/asm/u-boot-sandbox.h
@@ -77,14 +77,6 @@
 void sandbox_set_enable_pci_map(int enable);
 
 /**
- * sandbox_read_fdt_from_file() - Read a device tree from a file
- *
- * Read a device tree file from a host file and set it up for use as the
- * control FDT.
- */
-int sandbox_read_fdt_from_file(void);
-
-/**
  * sandbox_reset() - reset sandbox
  *
  * This functions implements the cold reboot of the sandbox. It relaunches the