[bsp, distro] Move parsec configuration recipe

The changes to the parsec configuration file should always be made on
cassini images and are not tied to the BSP but only dependent on the BSP
setting the correct machine feature to indicate the presence of trusted
services on the platform.

Changelog: bug
Signed-off-by: Drew Reed <Drew.Reed@arm.com>
Signed-off-by: Adam Johnston <adam.johnston@linaro.org>