Increase poll time on failure

Polling on failure causes increased CPU usage,
slow it down. Also always use update value instead
of setting value directly.

Tested-by: Turned off system and noticed lower cpu
usage.

Change-Id: I922ff016ba9dde9da77aa6dc95951d2f3d3f8259
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/include/sensor.hpp b/include/sensor.hpp
index 2f746da..a19b969 100644
--- a/include/sensor.hpp
+++ b/include/sensor.hpp
@@ -3,6 +3,7 @@
 #include <Thresholds.hpp>
 #include <sdbusplus/asio/object_server.hpp>
 
+constexpr size_t sensorFailedPollTimeMs = 5000;
 struct Sensor
 {
     virtual ~Sensor() = default;