Rename test_powercycle_loop.robot to test_bmc_reset_loop.robot

Based on the test use case in this suite, the logical step is to rename
to connect to the use cases in it.

Resolves  openbmc/openbmc-test-automation#1116

Change-Id: I2025167fce6828d2a4c7f84e921cbdb9dd04a2aa
diff --git a/extended/test_powercycle_loop.robot b/extended/test_bmc_reset_loop.robot
similarity index 100%
rename from extended/test_powercycle_loop.robot
rename to extended/test_bmc_reset_loop.robot