RedfishClientPkg/RedfishEventLib: restore TPL level

The TPL level in RedfishEventLib is TPL_CALLBACK by its design.
The TPL level was raised temporarily to TPL_NOTIFY in to work-around an
issue.

After the discussion with EDK2 Redfish group, a better solution has been
implemented. As the result, restore TPL level back to TPL_CALLBACK to
follow edk2 design.

SBIOS-1058

Signed-off-by: Nickle Wang <nicklew@nvidia.com>
Reviewed-by: Jake Garver <jake@nvidia.com>
Tested-by: Jake Garver <jake@nvidia.com>

RedfishClientPkg/Library/RedfishEventLib/RedfishEventLib.c

@@ -41,7 +41,7 @@ CreateReadyToProvisioningEvent (
 
   Status = gBS->CreateEventEx (
                   EVT_NOTIFY_SIGNAL,
-                  TPL_NOTIFY,
+                  TPL_CALLBACK,
                   (NotifyFunction == NULL ? EfiEventEmptyFunction : NotifyFunction),
                   NotifyContext,
                   &gEfiRedfishClientFeatureReadyToProvisioningGuid,
@@ -74,7 +74,7 @@ CreateAfterProvisioningEvent (
 
   Status = gBS->CreateEventEx (
                   EVT_NOTIFY_SIGNAL,
-                  TPL_NOTIFY,
+                  TPL_CALLBACK,
                   (NotifyFunction == NULL ? EfiEventEmptyFunction : NotifyFunction),
                   NotifyContext,
                   &gEfiRedfishClientFeatureAfterProvisioningGuid,