unit-test: Increase available debug information for test builds

Configuring `-Og` helps ensure `abi-dumper` has all the information it
would like for ABI analysis.

```
    ...
    [18/39] Generating abi-dump with a custom command
    Detect public symbols
    Reading debug-info
    WARNING: incompatible build option detected: -O0 (required -Og for better analysis)
    ...
```

Change-Id: Ia4d2add17a1e65bb480cb7003597af62c8e47bc2
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
1 file changed