fastboot: Move fastboot response functions to fastboot core

The functions and a few define to generate a fastboot message to be sent
back to the host were so far duplicated among the users.

Move them all to a common place.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/include/aboot.h b/include/aboot.h
index 30e4d36..18ff07a 100644
--- a/include/aboot.h
+++ b/include/aboot.h
@@ -9,9 +9,6 @@
 
 #define ROUNDUP(x, y)	(((x) + ((y) - 1)) & ~((y) - 1))
 
-void fastboot_fail(const char *s);
-void fastboot_okay(const char *s);
-
 static inline int is_sparse_image(void *buf)
 {
 	sparse_header_t *s_header = (sparse_header_t *)buf;
@@ -23,6 +20,6 @@
 	return 0;
 }
 
-void write_sparse_image(block_dev_desc_t *dev_desc,
-		disk_partition_t *info, const char *part_name,
-		void *data, unsigned sz);
+int write_sparse_image(block_dev_desc_t *dev_desc,
+		       disk_partition_t *info, const char *part_name,
+		       void *data, unsigned sz);