libffi: fix install location of host libffi headers

Seems that the header files for the host libffi headers
are installed in the wrong place.
i.e. $(STAGING_DIR_HOSTPKG)/lib/libffi-3.2.1/include
when it should be $(STAGING_DIR_HOSTPKG)/include

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

libs/libffi/Makefile

@@ -9,11 +9,11 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libffi
 PKG_VERSION:=3.2.1
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=ftp://sourceware.org/pub/libffi/
-PKG_MD5SUM:=83b89587607e3eb65c70d361f13bab43
+PKG_HASH:=d06ebb8e1d9a22d19e38d63fdb83954253f39bedc5d46232a05645685722ca37
 
 PKG_LICENSE:=MIT
 PKG_LICENSE_FILES:=LICENSE
@@ -78,5 +78,15 @@ define Package/libffi/install
 		$(1)/usr/lib/
 endef
 
+define Host/Install
+	$(call Host/Install/Default)
+	# Adjust host libffi headers ; the default rule does
+	# not seem to install them to the proper include folder
+	$(INSTALL_DIR) $(STAGING_DIR_HOSTPKG)/include
+	$(CP) \
+		$(STAGING_DIR_HOSTPKG)/lib/libffi-$(PKG_VERSION)/include/*.h \
+		$(STAGING_DIR_HOSTPKG)/include
+endef
+
 $(eval $(call HostBuild))
 $(eval $(call BuildPackage,libffi))