Remove JPEG 2000 plugin.

It is moving to the QtImageFormats module.

Change-Id: I1b7e05e01852ce51e93189d5fb04af9c89f0c807
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Jake Petroules <jake.petroules@petroules.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>