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/host-interface.cpp b/host-interface.cpp
index f6ba817..6500174 100644
--- a/host-interface.cpp
+++ b/host-interface.cpp
@@ -97,7 +97,7 @@
     ipmid_send_cmd_to_host(std::move(cmd));
 
     // Timer to ensure this function returns something within a reasonable time
-    phosphor::Timer hostAckTimer([hostCondition]() {
+    sdbusplus::Timer hostAckTimer([hostCondition]() {
         log<level::DEBUG>("currentFirmwareCondition: timer expired!");
         *(hostCondition.get()) = Host::FirmwareCondition::Off;
     });