is_extension_available is modified to handle errors by throwing
exceptions.
Contributes to #627
Change-Id: Ie9423df588892a0f8effa03d1cb48bf12400b983
Signed-off-by: Ellen Norris-Thompson <ellen.norris-thompson@arm.com>
Fixes#693 by returning `TEST_SKIP` instead of `TEST_FAIL` from the
`verifyImageSupport()` kernel helper function when
`checkForImageSupport()` reports the device does not support images.
