event: Use an event to replace last_stage_init()

Add a new event which handles this function. Convert existing use of
the function to use the new event instead.

Make sure that EVENT is enabled by affected boards, by selecting it from
the LAST_STAGE_INIT option. For x86, enable it by default since all boards
need it.

For controlcenterdc, inline the get_tpm() function and make sure the event
is not built in SPL.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/Kconfig b/common/Kconfig
index 0b09bd6..d916194 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -720,6 +720,7 @@
 
 config LAST_STAGE_INIT
 	bool "Call board-specific as last setup step"
+	select EVENT
 	help
 	  Some boards need to perform initialisation immediately before control
 	  is passed to the command-line interpreter (e.g. for initializations