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: I68d3968bcb359bee5ea0c9e695572b68fcf34136
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/requester/request.hpp b/requester/request.hpp
index 27d94fc..cb4e026 100644
--- a/requester/request.hpp
+++ b/requester/request.hpp
@@ -98,8 +98,8 @@
     sdeventplus::Event& event; //!< reference to PLDM daemon's main event loop
     uint8_t numRetries;        //!< number of request retries
     std::chrono::milliseconds
-        timeout;           //!< time to wait between each retry in milliseconds
-    phosphor::Timer timer; //!< manages starting timers and handling timeouts
+        timeout;            //!< time to wait between each retry in milliseconds
+    sdbusplus::Timer timer; //!< manages starting timers and handling timeouts
 
     /** @brief Sends the PLDM request message
      *