cmake: Install host packages to lib instead of lib64

Several CMake packages such as log4cplus and protobuf(-c) install to
lib64 instead of lib on some hosts. This completely breaks rpath linking.
Override it globally to avoid fixing each package individually.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Tested-by: Sebastian Kemper <sebastian_ml@gmx.net>

include/cmake.mk

@@ -103,6 +103,7 @@ define Host/Configure/Default
 			-DCMAKE_INSTALL_PREFIX=$(HOST_BUILD_PREFIX) \
 			-DCMAKE_PREFIX_PATH=$(HOST_BUILD_PREFIX) \
 			-DCMAKE_SKIP_RPATH=TRUE  \
+			-DCMAKE_INSTALL_LIBDIR=lib \
 			$(CMAKE_HOST_OPTIONS) \
 		$(HOST_CMAKE_SOURCE_DIR) \
 	)