CtsOpenGlPerf2TestCases: Increase timeout of GLReferenceBenchmark

1000 seconds aren't enough to some embedded devices since it doesn't
have GPU. Increase timeout of the benchmark to pass the CTS.

Bug: 63454520
Test: run cts -m CtsOpenGlPerf2TestCases on iot_imx7d_pico
Change-Id: I30f1297b17e33548e747fdcf2f10a665fc6f626b
1 file changed