travis.yml: add coverity support
travis.yml: add coverity support

Enables static analysis when pushing to a branch coverity_scan on github
See https://scan.coverity.com/travis_ci

Signed-off-by: Mike Holmes <ed44c09f4d7f698f5510adc894a872c73e08c8bd@linaro.org>
Signed-off-by: Maxim Uvarov <db4d16e02ae2d7493db430203537da8b2e34f290@linaro.org>

ravineet-singh/odp,mike-holmes-linaro/odp,dkrot/odp,ravineet-singh/odp,nmorey/odp,mike-holmes-linaro/odp,dkrot/odp,erachmi/odp,mike-holmes-linaro/odp,ravineet-singh/odp,nmorey/odp,erachmi/odp,mike-holmes-linaro/odp,nmorey/odp,nmorey/odp,dkrot/odp,ravineet-singh/odp,erachmi/odp,dkrot/odp,erachmi/odp