change header to specify 'on Linux'

Specify the test suite can be run on Linux because it is not
ARM specific.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Amit Kucheria <amit.kucheria@linaro.org>
diff --git a/Test.mk b/Test.mk
index 3c387db..655527c 100644
--- a/Test.mk
+++ b/Test.mk
@@ -1,5 +1,5 @@
 #
-# PM-QA validation test suite for the power management on ARM
+# PM-QA validation test suite for the power management on Linux
 #
 # Copyright (C) 2011, Linaro Limited.
 #