Makefile: Pass OF_SPL_REMOVE_PROPS to binman

Pass CONFIG_OF_SPL_REMOVE_PROPS to binman so that it can remove
properties correctly when producing FITs for SPL phases.

Signed-off-by: Simon Glass <sjg@chromium.org>

Makefile

@@ -1393,6 +1393,7 @@ cmd_binman = $(srctree)/tools/binman/binman $(if $(BINMAN_DEBUG),-D) \
 		-a tpl-dtb=$(CONFIG_TPL_OF_REAL) \
 		-a vpl-dtb=$(CONFIG_VPL_OF_REAL) \
 		-a pre-load-key-path=${PRE_LOAD_KEY_PATH} \
+		-a of-spl-remove-props=$(CONFIG_OF_SPL_REMOVE_PROPS) \
 		$(BINMAN_$(@F))
 
 OBJCOPYFLAGS_u-boot.ldr.hex := -I binary -O ihex

tools/binman/etype/fit.py

@@ -210,7 +210,8 @@ class Entry_fit(Entry_section):
 
     Note that the `of-spl-remove-props` entryarg can be used to indicate
     additional properties to remove. It is often used to remove properties like
-    `clock-names` and `pinctrl-names` which are not needed in SPL builds.
+    `clock-names` and `pinctrl-names` which are not needed in SPL builds. This
+    value is automatically passed to binman by the U-Boot build.
 
     See :ref:`fdtgrep_filter` for more information.