cmake-conf: ensure conf is also built with the intuitive `cmake`

fixes #2026

src/cmake-conf.mk

@@ -8,6 +8,9 @@ $(PKG)_DEPS    := $(BUILD)~$(PKG)
 $(PKG)_FILE_DEPS := $(wildcard $(PWD)/src/cmake/conf/*)
 $(PKG)_DEPS_$(BUILD) := cmake
 
+# ensure conf is also built for a minimal `make cc cmake`
+cmake: cmake-conf
+
 define $(PKG)_BUILD
     # create the CMake toolchain file using template
     # individual packages (e.g. hdf5) should add their