kconfig: Add -MP option so .d files include empty targets

Prevents make-level errors when switching IDF versions, as headers may be removed.

Similar to some mentioned here:
https://github.com/espressif/esp-idf/issues/712

diff --git a/tools/kconfig/Makefile b/tools/kconfig/Makefile
index b91cbc28280d3790ec0bababc3a51de55e07cefa..9fc367b454087b1e49c92a903392a697c80b4910 100644 (file)
--- a/tools/kconfig/Makefile
+++ b/tools/kconfig/Makefile
@@ -165,7 +165,7 @@ check-lxdialog  := $(SRCDIR)/lxdialog/check-lxdialog.sh
 # Use recursively expanded variables so we do not call gcc unless
 # we really need to do so. (Do not call gcc as part of make mrproper)
 CFLAGS += $(shell $(CONFIG_SHELL) $(check-lxdialog) -ccflags) \
-                    -DLOCALE -MMD
+                    -DLOCALE -MMD -MP
 
 CFLAGS += -I "." -I "${SRCDIR}"