dh_clideps does not understand the "dllentry" syntax.
Take the config files from the Ubuntu package which uses the "target" syntax.

Map libGL.so to libGLU.so.1
Index: openra-20160508/thirdparty/fetch-thirdparty-deps.sh
===================================================================
--- openra-20160508.orig/thirdparty/fetch-thirdparty-deps.sh	2016-05-08 15:36:33.905224396 +0200
+++ openra-20160508/thirdparty/fetch-thirdparty-deps.sh	2016-05-08 16:01:24.615886385 +0200
@@ -69,6 +69,7 @@
 	cp ./SharpFont/lib/net20/SharpFont* .
 	cp ./SharpFont/config/SharpFont.dll.config .
 	rm -rf SharpFont SharpFont.Dependencies
+	patch -p1 < ../../debian/patches/sharpfont.patch
 fi
 
 if [ ! -f nunit.framework.dll ]; then
@@ -104,6 +105,7 @@
 	echo "Fetching SDL2-CS from GitHub."
 	curl -s -L -O https://github.com/OpenRA/SDL2-CS/releases/download/20151227/SDL2-CS.dll
 	curl -s -L -O https://github.com/OpenRA/SDL2-CS/releases/download/20151227/SDL2-CS.dll.config
+	patch -p1 < ../../debian/patches/sdl2_config.patch
 fi
 
 if [ ! -f OpenAL-CS.dll -o ! -f OpenAL-CS.dll.config ]; then