imagetool: make the image_save_datafile() available to all image types

Move the image_save_datafile() function from an U-Multi specific file
(default_image.c) to a file common to all image types (image.c). And rename it
to genimg_save_datafile(), to make clear it is useful for any image type.

Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>
diff --git a/common/image.c b/common/image.c
index ad7a46d..a911aa9 100644
--- a/common/image.c
+++ b/common/image.c
@@ -756,7 +756,7 @@
  * genimg_get_image - get image from special storage (if necessary)
  * @img_addr: image start address
  *
- * genimg_get_image() checks if provided image start adddress is located
+ * genimg_get_image() checks if provided image start address is located
  * in a dataflash storage. If so, image is moved to a system RAM memory.
  *
  * returns:
diff --git a/tools/default_image.c b/tools/default_image.c
index 0a0792e..a92fa80 100644
--- a/tools/default_image.c
+++ b/tools/default_image.c
@@ -117,32 +117,6 @@
 	image_set_hcrc(hdr, checksum);
 }
 
-static int image_save_datafile(struct image_tool_params *params,
-			       ulong file_data, ulong file_len)
-{
-	int dfd;
-	const char *datafile = params->outfile;
-
-	dfd = open(datafile, O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
-		   S_IRUSR | S_IWUSR);
-	if (dfd < 0) {
-		fprintf(stderr, "%s: Can't open \"%s\": %s\n",
-			params->cmdname, datafile, strerror(errno));
-		return -1;
-	}
-
-	if (write(dfd, (void *)file_data, file_len) != (ssize_t)file_len) {
-		fprintf(stderr, "%s: Write error on \"%s\": %s\n",
-			params->cmdname, datafile, strerror(errno));
-		close(dfd);
-		return -1;
-	}
-
-	close(dfd);
-
-	return 0;
-}
-
 static int image_extract_datafile(void *ptr, struct image_tool_params *params)
 {
 	const image_header_t *hdr = (const image_header_t *)ptr;
@@ -170,7 +144,7 @@
 	}
 
 	/* save the "data file" into the file system */
-	return image_save_datafile(params, file_data, file_len);
+	return imagetool_save_datafile(params->outfile, file_data, file_len);
 }
 
 /*
diff --git a/tools/imagetool.c b/tools/imagetool.c
index e4de7af..a25b86b 100644
--- a/tools/imagetool.c
+++ b/tools/imagetool.c
@@ -113,3 +113,30 @@
 
 	return retval;
 }
+
+int imagetool_save_datafile(
+	const char *file_name,
+	ulong file_data,
+	ulong file_len)
+{
+	int dfd;
+
+	dfd = open(file_name, O_RDWR | O_CREAT | O_TRUNC | O_BINARY,
+		   S_IRUSR | S_IWUSR);
+	if (dfd < 0) {
+		fprintf(stderr, "Can't open \"%s\": %s\n",
+			file_name, strerror(errno));
+		return -1;
+	}
+
+	if (write(dfd, (void *)file_data, file_len) != (ssize_t)file_len) {
+		fprintf(stderr, "Write error on \"%s\": %s\n",
+			file_name, strerror(errno));
+		close(dfd);
+		return -1;
+	}
+
+	close(dfd);
+
+	return 0;
+}
diff --git a/tools/imagetool.h b/tools/imagetool.h
index eb2750c..44d9380 100644
--- a/tools/imagetool.h
+++ b/tools/imagetool.h
@@ -181,6 +181,23 @@
 	struct image_type_params *tparams,
 	struct image_tool_params *params);
 
+/**
+ * imagetool_save_datafile - store data into a file
+ * @file_name: name of the destination file
+ * @file_data: data to be written
+ * @file_len: the amount of data to store
+ *
+ * imagetool_save_datafile() store file_len bytes of data pointed by file_data
+ * into the file name by file_name.
+ *
+ * returns:
+ *     zero in case of success or a negative value if fail.
+ */
+int imagetool_save_datafile(
+	const char *file_name,
+	ulong file_data,
+	ulong file_len);
+
 /*
  * There is a c file associated with supported image type low level code
  * for ex. default_image.c, fit_image.c