testsuite.at: fix: conditionally enable 'ecu/ecu_fr_test'

In the 'ecu/ecu_fr_test' we have a processing queue with Full Rate
decoder block, which depends on libgsm. If libgsm isn't available,
the test will fail. Let's enable this test conditionally.

Change-Id: I74cf0e9de1e2f65e7227ee1565f12622bb55cabe
1 file changed