tests: add gpio driver test case

the commit include 5 ztest cases, cover the basic gpio APIs
including callback relevant and pin read/write functions.
It proves workable on intel quark c1000 and
arduino 101 platform

Change-Id: Iab30aa841cfa440c1f773b5a8c5ce0d68346c353
Signed-off-by: jing wang <jing.j.wang@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>