part: Drop disk_partition_t typedef

We should not be using typedefs and these make it harder to use
forward declarations (to reduce header file inclusions). Drop the typedef.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/disk/part_amiga.c b/disk/part_amiga.c
index 5a2bb71..5a17d11 100644
--- a/disk/part_amiga.c
+++ b/disk/part_amiga.c
@@ -291,7 +291,7 @@
  * Get info about a partition
  */
 static int part_get_info_amiga(struct blk_desc *dev_desc, int part,
-				    disk_partition_t *info)
+				    struct disk_partition *info)
 {
     struct partition_block *p = find_partition(dev_desc, part-1);
     struct amiga_part_geometry *g;