Modify clearSEL

After clearing the log, adding the log does not start from 1,
use deleteAll method to clearSEL.

Tested :Run `ipmitool sel clear&&ipmitool sel list`:
 1 | 05/23/21 | 09:01:11 UTC | Event Logging Disabled #0x8b | Log area reset/cleared | Asserted

Signed-off-by: Lotus Xu <xuxiaohan@bytedance.com>
Change-Id: Ic1e63c3334adf77f54f36bebfed459138a215f06
diff --git a/selutility.hpp b/selutility.hpp
index 91c4eaf..fa28fb1 100644
--- a/selutility.hpp
+++ b/selutility.hpp
@@ -22,6 +22,10 @@
 static constexpr auto logEntryIntf = "xyz.openbmc_project.Logging.Entry";
 static constexpr auto logDeleteIntf = "xyz.openbmc_project.Object.Delete";
 
+static constexpr auto logObj = "/xyz/openbmc_project/logging";
+static constexpr auto logIntf = "xyz.openbmc_project.Collection.DeleteAll";
+static constexpr auto logDeleteAllMethod = "DeleteAll";
+
 static constexpr auto propIntf = "org.freedesktop.DBus.Properties";
 
 using ObjectPaths = std::vector<std::string>;