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/cmd/ab_select.c b/cmd/ab_select.c
index 7c8f2ee..d0d957d 100644
--- a/cmd/ab_select.c
+++ b/cmd/ab_select.c
@@ -11,7 +11,7 @@
 {
 	int ret;
 	struct blk_desc *dev_desc;
-	disk_partition_t part_info;
+	struct disk_partition part_info;
 	char slot[2];
 
 	if (argc != 4)