presence: build: Add yaml file to generated deps

Makefile updates such that updates to the YAML file result
in a retrigger of the python script.

Change-Id: I83b637f71dc380a56be0fd40390176d3b201b29a
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/presence/Makefile.am b/presence/Makefile.am
index 10a7363..b56ed4e 100644
--- a/presence/Makefile.am
+++ b/presence/Makefile.am
@@ -21,5 +21,5 @@
 
 BUILT_SOURCES = fan_detect_defs.cpp
 
-fan_detect_defs.cpp: ${srcdir}/gen-fan-detect-defs.py
-	$(AM_V_GEN)$(GEN_FAN_DETECT_DEFS) > $@
+fan_detect_defs.cpp: ${srcdir}/gen-fan-detect-defs.py $(FAN_DETECT_YAML_FILE)
+	$(AM_V_GEN)$(GEN_FAN_DETECT_DEFS) > $(builddir)/$@