PEL: Set platform SAI LED group

There is now an LED group to set when the platform SAI LED needs to be
asserted when handling the service indicators for PEL callouts.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I2af66c8c1820c131e1d4d7dede802b5f128b79a4
diff --git a/extensions/openpower-pels/service_indicators.cpp b/extensions/openpower-pels/service_indicators.cpp
index 3f934c7..7f795f9 100644
--- a/extensions/openpower-pels/service_indicators.cpp
+++ b/extensions/openpower-pels/service_indicators.cpp
@@ -25,6 +25,9 @@
 
 using namespace phosphor::logging;
 
+static constexpr auto platformSaiLedGroup =
+    "/xyz/openbmc_project/led/groups/platform_system_attention_indicator";
+
 std::unique_ptr<Policy> getPolicy(const DataInterfaceBase& dataIface)
 {
     // At the moment there is just one type of policy.
@@ -85,8 +88,17 @@
 
     if (sai)
     {
-        log<level::INFO>("The System Attention Indicator needs to be turned "
-                         "on, when available");
+        try
+        {
+            _dataIface.assertLEDGroup(platformSaiLedGroup, true);
+        }
+        catch (const std::exception& e)
+        {
+            log<level::ERR>(
+                fmt::format("Failed to assert platform SAI LED group: {}",
+                            e.what())
+                    .c_str());
+        }
     }
 }