While packaging for homebrew, I ran into some rpath issue when building the tools.
```
$ /opt/homebrew/Cellar/liblc3/1.1.0/bin/elc3 -h
dyld[72986]: Library not loaded: @rpath/liblc3.1.dylib
Referenced from: <1B4E9174-0A9C-3907-8487-40BBBE5B52CB> /opt/homebrew/Cellar/liblc3/1.1.0/bin/elc3
Reason: no LC_RPATH's found
Abort trap: 6
```
This patch is for fixing the rpath ref issue.
Signed-off-by: Rui Chen <rui@chenrui.dev>