Update 08-porting-to-hip.md

Author: csccva

docs/08-porting-to-hip.md

@@ -204,6 +204,6 @@ implementations
 **Note!** Not all features have one-to-one equivalent!
 
 - **warp size** is 32 vs. **wave size** of 64
-- `__shfl_down_sync` ⇒ → `__shfl_down`
-- dynamic parallelism not supported
-- cooperative groups???
+- `__shfl_down_sync` ⇒ `__shfl_down`
+- dynamic parallelism not supported on AMD devices
+- cooperative groups not supported on AMD devices