tests: benchmarks: power_consumption: fix fixture.

Change test fixture to use correct test setup.

Signed-off-by: Bartlomiej Buczek <[email protected]>

Author: nordic-babu

tests/benchmarks/power_consumption/lpcomp/testcase.yaml

@@ -9,7 +9,7 @@ tests:
       - nrf54l15dk/nrf54l15/cpuapp
     harness: pytest
     harness_config:
-      fixture: ppk_power_measure
+      fixture: gpio_loopback
       pytest_root:
         - "${CUSTOM_ROOT_TEST_DIR}/test_measure_power_consumption.py::test_thread_suspend_resume_lpcomp_54L"
   benchmarks.power_consumption.lpcomp_nrf54h:
@@ -22,6 +22,6 @@ tests:
       SB_CONF_FILE=sysbuild/nrf54h20dk_nrf54h20_cpurad.conf
     harness: pytest
     harness_config:
-      fixture: ppk_power_measure
+      fixture: gpio_loopback
       pytest_root:
         - "${CUSTOM_ROOT_TEST_DIR}/test_measure_power_consumption.py::test_thread_suspend_resume_lpcomp_54H"