samples: gpio: sanitize test and remove obsolete options

- CONFIG_GPIO_DW_0_BITS is not longer available
- Use default printk
- Do not enable debug
- remove useless whitelist in testcase.ini, we already whitelist
  boards

Change-Id: If21795d544e268c26a757b697ce3c9f2e56db65f
Signed-off-by: Anas Nashif <anas.nashif@intel.com>