Add tracing for board config to dumpconfig

Test: build/make/ci/dump_product_config
Change-Id: I0667ef0e4427d396cedb03eaf2a314a789947e98
diff --git a/core/board_config.mk b/core/board_config.mk
index d3f0493..5606964 100644
--- a/core/board_config.mk
+++ b/core/board_config.mk
@@ -237,6 +237,7 @@
   .KATI_READONLY := TARGET_DEVICE_DIR
 endif
 
+$(call dump-phase-start,BOARD,,,, build/make/core/board_config.mk)
 ifndef RBC_PRODUCT_CONFIG
 include $(board_config_mk)
 else
@@ -261,6 +262,7 @@
 
   include $(OUT_DIR)/rbc/rbc_board_config_results.mk
 endif
+$(call dump-phase-end, build/make/core/board_config.mk)
 
 ifneq (,$(and $(TARGET_ARCH),$(TARGET_ARCH_SUITE)))
   $(error $(board_config_mk) erroneously sets both TARGET_ARCH and TARGET_ARCH_SUITE)