graphics_GLBench: remove metrics for different SKU

This SKU list is added to distinguish the difference in chromeperf.
For metrics within the same graph, crosbolt concatenates graph name
and sub-metric name to represent it on its website.
This is problematic to list them in crosbolt. Given crosbolt can
identify SKU by default. Drop this.

BUG=chromium:1024553, b:146477388
TEST=None

Change-Id: I92e6be2d00841ffa41f65766941b300a3b852ced
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/1971752
Tested-by: Ilja H. Friedel <ihf@chromium.org>
Commit-Queue: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Ilja H. Friedel <ihf@chromium.org>
Reviewed-by: Chung-yih Wang <cywang@chromium.org>
Auto-Submit: Po-Hsien Wang <pwang@chromium.org>
diff --git a/client/site_tests/graphics_GLBench/graphics_GLBench.py b/client/site_tests/graphics_GLBench/graphics_GLBench.py
index f47e6ac..565ec7a 100644
--- a/client/site_tests/graphics_GLBench/graphics_GLBench.py
+++ b/client/site_tests/graphics_GLBench/graphics_GLBench.py
@@ -199,15 +199,6 @@
             units=unit,
             higher_is_better=higher,
             graph=perf_value_name)
-        # Add extra value to the graph distinguishing different boards.
-        variant = utils.get_board_with_frequency_and_memory()
-        desc = '%s-%s' % (perf_value_name, variant)
-        self.output_perf_value(
-            description=desc,
-            value=testrating,
-            units=unit,
-            higher_is_better=higher,
-            graph=perf_value_name)
 
       # Classify result image.
       if testrating == -1.0: