arago.conf: re-enable "opencv" distro feature
arago.conf: re-enable "opencv" distro feature

Corresponding fixes for external-arm-toolchain have been accepted upstream.

Signed-off-by: Denys Dmytriyenko <d29de71aea38aad3a87d486929cb0aad173ae612@ti.com>

rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago,rcn-ee/meta-arago