makefile: Pass OpenSBI blob to binman make rules

This updates the make rules to pass OpenSBI blob to binman.
Signed-off-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>

Makefile

@@ -1285,6 +1285,7 @@ cmd_binman = $(srctree)/tools/binman/binman $(if $(BINMAN_DEBUG),-D) \
 		-I . -I $(srctree) -I $(srctree)/board/$(BOARDDIR) \
 		-I arch/$(ARCH)/dts -a of-list=$(CONFIG_OF_LIST) \
 		-a atf-bl31-path=${BL31} \
+		-a opensbi-path=${OPENSBI} \
 		-a default-dt=$(default_dt) \
 		-a scp-path=$(SCP) \
 		-a spl-bss-pad=$(if $(CONFIG_SPL_SEPARATE_BSS),,1) \