Makefile: Fix inclusion of the config-devices.mak.d Kconfig dependencies

The Makefile tries to include device Kconfig dependencies via

 -include $(SUBDIR_DEVICES_MAK_DEP)

and thus expects files that match *-softmmu/config-devices.mak.d ...
however, the minikconf script currently generates files a la
"*-softmmu-config.devices.mak.d" instead, so the dependency files
simply got ignored so far. For example, after a "touch hw/arm/Kconfig",
the arm-softmmu/config-devices.mak file is currently not re-generated.
Fix it by putting the dependency files in the *-softmmu folders now.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
diff --git a/Makefile b/Makefile
index 4a8ae0e..66d5c65 100644
--- a/Makefile
+++ b/Makefile
@@ -350,7 +350,7 @@
 # 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 $< $(MINIKCONF_INPUTS) \
     CONFIG_KVM=$(CONFIG_KVM) \
     CONFIG_SPICE=$(CONFIG_SPICE) \
     CONFIG_IVSHMEM=$(CONFIG_IVSHMEM) \