update README.md for rocgdb

Author: vmnit

README.md

@@ -8,7 +8,7 @@ hipcc <src_filename> -o <out_binary_name>
 ```
 Note: cmake flow is not updated for the above HIP programs.
 
-For more details, please refer README.md in src/hip directory.
+For more details, please refer `README.md` at location: `src/hip/README.md`
 
 # Using taskflow as submodule for parallel programming, so run following to initialize it
 ```

src/hip/README.md

@@ -36,3 +36,9 @@ roc-obj-extract file://sq_cube_no_hipstream#offset=16384&size=6648
 
 It will generate the .co file which can be disassembled using llvm-obj-dump. But couldn't find the utility in the rocm installation, so roc-obj can be used instead as mentioned above.
 
+# rocgdb
+
+```
+hipcc -g vector_add_v1.cxx -o vector_add_v1_dbg -I../
+rocgdb vector_add_v1_dbg
+```