feat(stm32mp1): add the platform specific build for tools

Add cert_create and fiptool specific files to add the platform
addons to the generic tools.

Change-Id: Ifa600241cdf32b495cc65edccddab47c3796b77d
Signed-off-by: Lionel Debieve <lionel.debieve@foss.st.com>
diff --git a/plat/st/stm32mp1/cert_create_tbbr.mk b/plat/st/stm32mp1/cert_create_tbbr.mk
new file mode 100644
index 0000000..5b1a3ed
--- /dev/null
+++ b/plat/st/stm32mp1/cert_create_tbbr.mk
@@ -0,0 +1,19 @@
+#
+# Copyright (c) 2022, STMicroelectronics - All Rights Reserved
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+# Override TBBR Cert to update generic certificate
+
+$(eval $(call add_define,PDEF_CERTS))
+
+PLAT_INCLUDE	+= -I${PLAT_DIR}include
+
+src/stm32mp1_tbb_cert.o: ${PLAT_DIR}stm32mp1_tbb_cert.c
+	${Q}${HOSTCC} -c ${HOSTCCFLAGS} ${INC_DIR} $< -o $@
+
+PLAT_OBJECTS	= src/stm32mp1_tbb_cert.o
+
+OBJECTS		+= $(PLAT_OBJECTS)
+