RFR(XS): 8191943: [TESTBUG] docker/TestCPUAwareness fails on machine with 2 CPUs

[mikhailo]

Could you, please, review this simple fix? It limits test cases in 
TestCPUAwareness.java
based on the number of processors available.

     JBS: https://bugs.openjdk.java.net/browse/JDK-8191943
     Webrev: http://cr.openjdk.java.net/~mseledtsov/8191943.00/
     Testing:
         1. Locally: exercised the affected test locally on Linux-x64
         2. Exercised the affected test on 2 processor machine
         3. Exercise the affected test via automated distributed test system
            In progress

Misha