dm: part: Add a cast to avoid a compiler warning

In part_amiga.c the name is unsigned but bcpl_strcpy() requires a signed
pointer. Add a cast to fix the warning.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Stephen Warren <swarren@nvidia.com>

disk/part_amiga.c

@@ -304,7 +304,7 @@ int get_partition_info_amiga(struct blk_desc *dev_desc, int part,
     info->start = g->low_cyl  * g->block_per_track * g->surfaces;
     info->size  = (g->high_cyl - g->low_cyl + 1) * g->block_per_track * g->surfaces - 1;
     info->blksz = rdb.block_bytes;
-    bcpl_strcpy(info->name, p->drive_name);
+    bcpl_strcpy((char *)info->name, p->drive_name);
 
 
     disk_type = g->dos_type;