Add bios post checking support

Some sensors aren't available until after bios post
add support to check for post when needed.

Tested-by: SSB temp no longer asserted thresholds before
bios post.

Change-Id: I9251c2c501e082ef4bb0e9eb7909dc137771e120
Signed-off-by: James Feist <james.feist@linux.intel.com>
diff --git a/src/IpmbSensor.cpp b/src/IpmbSensor.cpp
index 71d4a5b..af1f725 100644
--- a/src/IpmbSensor.cpp
+++ b/src/IpmbSensor.cpp
@@ -166,6 +166,10 @@
     {
         return;
     }
+    else if (readState == PowerState::biosPost && !hasBiosPost())
+    {
+        return;
+    }
     thresholds::checkThresholds(this);
 }
 
@@ -306,6 +310,16 @@
                         dbusConnection, io, name, pathPair.first, objectServer,
                         std::move(sensorThresholds), deviceAddress);
 
+                    auto findPowerState = entry.second.find("PowerState");
+
+                    if (findPowerState != entry.second.end())
+                    {
+                        std::string powerState = std::visit(
+                            VariantToStringVisitor(), findPowerState->second);
+
+                        setReadState(powerState, sensor->readState);
+                    }
+
                     if (sensorClass == "PxeBridgeTemp")
                     {
                         sensor->type = IpmbType::PXE1410CVR;