event: signal when livetree has been built

OF_LIVE offers a variety of benefits, one of them being that the live
tree can be modified without caring about the underlying FDT. This is
particularly valuable for working around U-Boot limitations like lacking
USB superspeed support on Qualcomm platforms, no runtime OTG, or
peripherals like the sdcard being broken (and displaying potentially
worrying error messages).

Add an event to signal when the live tree has been built so that we can
apply fixups to it directly before devices are bound.

Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
diff --git a/common/event.c b/common/event.c
index dda569d..8d7513e 100644
--- a/common/event.c
+++ b/common/event.c
@@ -48,6 +48,9 @@
 
 	/* main loop events */
 	"main_loop",
+
+	/* livetree has been built */
+	"of_live_init",
 };
 
 _Static_assert(ARRAY_SIZE(type_name) == EVT_COUNT, "event type_name size");