Makefile: simplify MINIKCONF rules

There is no reason to write MINIKCONF_DEPS manually, since minikconf.py
emits a dependency file, and also no reason to list multiple Kconfig
files on the command line since they can be included from a master file
in the top-level source directory.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Kconfig

@@ -0,0 +1,4 @@
+source Kconfig.host
+source backends/Kconfig
+source accel/Kconfig
+source hw/Kconfig

Makefile

@@ -404,7 +404,7 @@ endif
 # This has to be kept in sync with Kconfig.host.
 MINIKCONF_ARGS = \
     $(CONFIG_MINIKCONF_MODE) \
-    $@ $*/config-devices.mak.d $< $(MINIKCONF_INPUTS) \
+    $@ $*/config-devices.mak.d $< $(SRC_PATH)/Kconfig \
     CONFIG_TCG=$(CONFIG_TCG) \
     CONFIG_KVM=$(CONFIG_KVM) \
     CONFIG_SPICE=$(CONFIG_SPICE) \
@@ -419,15 +419,9 @@ MINIKCONF_ARGS = \
     CONFIG_LINUX=$(CONFIG_LINUX) \
     CONFIG_PVRDMA=$(CONFIG_PVRDMA)
 
-MINIKCONF_INPUTS = $(SRC_PATH)/Kconfig.host \
-                   $(SRC_PATH)/backends/Kconfig \
-                   $(SRC_PATH)/accel/Kconfig \
-                   $(SRC_PATH)/hw/Kconfig
-MINIKCONF_DEPS = $(MINIKCONF_INPUTS) \
-                 $(wildcard $(SRC_PATH)/hw/*/Kconfig)
 MINIKCONF = $(PYTHON) $(SRC_PATH)/scripts/minikconf.py
 
-$(SUBDIR_DEVICES_MAK): %/config-devices.mak: default-configs/%.mak $(MINIKCONF_DEPS) $(BUILD_DIR)/config-host.mak
+$(SUBDIR_DEVICES_MAK): %/config-devices.mak: default-configs/%.mak $(SRC_PATH)/Kconfig $(BUILD_DIR)/config-host.mak
 	$(call quiet-command, $(MINIKCONF) $(MINIKCONF_ARGS) \
 		> $@.tmp, "GEN", "$@.tmp")
 	$(call quiet-command, if test -f $@; then \