testing: don't nest build for fp-test

Re-calling the main make is counter-productive and really messes up
with parallel builds. Just ensure we have built the pre-requisites
before we build the fp-test bits. If the user builds manually just
complain if the parent build hasn't got the bits we need.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NEmilio G. Cota <cota@braap.org>

tests/Makefile.include

@@ -969,7 +969,7 @@ FP_TEST_BIN=$(BUILD_DIR)/tests/fp/fp-test
 
 # the build dir is created by configure
 .PHONY: $(FP_TEST_BIN)
-$(FP_TEST_BIN):
+$(FP_TEST_BIN): config-host.h $(test-util-obj-y)
 	$(call quiet-command, \
 	 	$(MAKE) $(SUBDIR_MAKEFLAGS) -C $(dir $@) V="$(V)" $(notdir $@), \
 	         "BUILD", "$(notdir $@)")

tests/fp/Makefile

@@ -554,15 +554,13 @@ TF_OBJS_LIB += $(TF_OBJS_TEST)
 
 BINARIES := fp-test$(EXESUF) fp-bench$(EXESUF)
 
-# everything depends on config-host.h because platform.h includes it
-all: $(BUILD_DIR)/config-host.h
-	$(MAKE) $(BINARIES)
+# We require artefacts from the main build including config-host.h
+# because platform.h includes it. Rather than re-invoking the main
+# build we just error out if things aren't there.
+$(LIBQEMUUTIL) $(BUILD_DIR)/config-host.h:
+	$(error $@ missing, re-run parent build)
 
-$(LIBQEMUUTIL):
-	$(MAKE) -C $(BUILD_DIR) libqemuutil.a
-
-$(BUILD_DIR)/config-host.h:
-	$(MAKE) -C $(BUILD_DIR) config-host.h
+all: $(BUILD_DIR)/config-host.h $(BINARIES)
 
 # libtestfloat.a depends on libsoftfloat.a, so specify it first
 FP_TEST_LIBS := libtestfloat.a libsoftfloat.a $(LIBQEMUUTIL)