meta-bletchley: elimiate gpiomon event messages

Add silent option to elimiate event log messages from gpiomon command.

Signed-off-by: Potin Lai <potin.lai@quantatw.com>
Change-Id: I15726bdeb510b7b7771a040656a41d84aae64d7f
diff --git a/meta-facebook/meta-bletchley/recipes-bletchley/plat-tools/files/bletchley-common-functions b/meta-facebook/meta-bletchley/recipes-bletchley/plat-tools/files/bletchley-common-functions
index 49bca93..d0a27dd 100644
--- a/meta-facebook/meta-bletchley/recipes-bletchley/plat-tools/files/bletchley-common-functions
+++ b/meta-facebook/meta-bletchley/recipes-bletchley/plat-tools/files/bletchley-common-functions
@@ -49,7 +49,7 @@
         return 1
     fi
 
-    timeout "$TIMEOUT_SEC" gpiomon --falling-edge --num-events=1 "${GPIO_INFO[0]}" "${GPIO_INFO[1]%$'\n'}"
+    timeout "$TIMEOUT_SEC" gpiomon --silent --falling-edge --num-events=1 "${GPIO_INFO[0]}" "${GPIO_INFO[1]%$'\n'}"
 }
 
 set_fan()