[source] rssileds: Fix build with external toolchains

[LEDE Commits]

jow pushed a commit to source.git, branch lede-17.01:
https://git.lede-project.org/2dd9b62f82afba5dd1e7534cecfadad871d85885

commit 2dd9b62f82afba5dd1e7534cecfadad871d85885
Author: Florian Fainelli <f.fainelli at gmail.com>
AuthorDate: Sun Feb 12 18:34:53 2017 -0800

    rssileds: Fix build with external toolchains
    
    Pass down TARGET_CPPFLAGS for path to header files, and append the
    libraries we depend on in TARGET_LDFLAGS. Put TARGET_LDFLAGS at the end
    of the command line as is required by modern GCC/binutils.
    
    Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
    (cherry picked from commit 30159b3886849f94cd065ecece7ac988bfb89548)
---
 package/network/utils/rssileds/Makefile | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/package/network/utils/rssileds/Makefile b/package/network/utils/rssileds/Makefile
index e475bcd..d3fb66a 100644
--- a/package/network/utils/rssileds/Makefile
+++ b/package/network/utils/rssileds/Makefile
@@ -29,9 +29,11 @@ endef
 define Build/Configure
 endef
 
+TARGET_LDFLAGS += -liwinfo -luci -lubox -lnl-tiny
+
 define Build/Compile
-	$(TARGET_CC) $(TARGET_CFLAGS) -Wall -liwinfo \
-		-o $(PKG_BUILD_DIR)/rssileds $(PKG_BUILD_DIR)/rssileds.c
+	$(TARGET_CC) $(TARGET_CFLAGS) $(TARGET_CPPFLAGS) -Wall \
+		-o $(PKG_BUILD_DIR)/rssileds $(PKG_BUILD_DIR)/rssileds.c $(TARGET_LDFLAGS)
 endef
 
 define Package/rssileds/install