Add energy scale test case to skip list.
Add energy scale test case to skip list.

Add a test case to the skip list:
 Escale_System_On_And_PL_Disabled in systest/test_power_capping.robot.
This TC will fail until openbmc/openbmc#2379 is resolved.

Resolves  openbmc/openbmc-test-automation#1021
Change-Id: I5cfaa69eefc432ac30126d1632cabe307f0013f2
Signed-off-by: Steven Sombar <fb37bb6ac5c2258e1cbf80690dea88925949957e@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation