sdbusplus: avoid deprecated phosphor::Timer

sdbusplus had an older type named `phosphor::Timer` which was
recently renamed to `sdbusplus::Timer`.  Update the code to use
the new type alias.

Change-Id: If69434b3a3639b8f97ab16cab5da4d70e3379cb2
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/ipmid-new.cpp b/ipmid-new.cpp
index 1b123ed..9e12897 100644
--- a/ipmid-new.cpp
+++ b/ipmid-new.cpp
@@ -840,7 +840,7 @@
 
     // TODO: Hack to keep the sdEvents running.... Not sure why the sd_event
     //       queue stops running if we don't have a timer that keeps re-arming
-    phosphor::Timer t2([]() { ; });
+    sdbusplus::Timer t2([]() { ; });
     t2.start(std::chrono::microseconds(500000), true);
 
     // TODO: Remove all vestiges of sd_event from phosphor-host-ipmid