index.md: add edison link

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>
coverity: Fix issues found by coverity scan

* Fix a few resource leaks in error conditions
* Makes strtol() calls safer in pwm module
* Make sure buffer is terminated after read() in aio

Signed-off-by: Brendan Le Foll <brendan.le.foll@intel.com>