depends: reuse _config_opts for CMake options

This will allow us to use the existing machinery for filtering by
arch, os, debug/release, etc.

For example, the following becomes possible for libevent:

$(package)_config_opts_release=-DEVENT__DISABLE_DEBUG_MODE

Now the define is only set when not building depends with DEBUG=1

Author: theuni

depends/funcs.mk

@@ -176,7 +176,7 @@ $(1)_cmake=env CC="$$($(1)_cc)" \
                CXX="$$($(1)_cxx)" \
                CXXFLAGS="$$($(1)_cppflags) $$($(1)_cxxflags)" \
                LDFLAGS="$$($(1)_ldflags)" \
-             cmake -DCMAKE_INSTALL_PREFIX:PATH="$$($($(1)_type)_prefix)" $$($(1)_cmake_opts)
+             cmake -DCMAKE_INSTALL_PREFIX:PATH="$$($($(1)_type)_prefix)" $$($(1)_config_opts)
 ifeq ($($(1)_type),build)
 $(1)_cmake += -DCMAKE_INSTALL_RPATH:PATH="$$($($(1)_type)_prefix)/lib"
 else

depends/packages/libmultiprocess.mk

@@ -10,8 +10,8 @@ endif
 
 define $(package)_set_vars :=
 ifneq ($(host),$(build))
-$(package)_cmake_opts := -DCAPNP_EXECUTABLE="$$(native_capnp_prefixbin)/capnp"
-$(package)_cmake_opts += -DCAPNPC_CXX_EXECUTABLE="$$(native_capnp_prefixbin)/capnpc-c++"
+$(package)_config_opts := -DCAPNP_EXECUTABLE="$$(native_capnp_prefixbin)/capnp"
+$(package)_config_opts += -DCAPNPC_CXX_EXECUTABLE="$$(native_capnp_prefixbin)/capnpc-c++"
 endif
 endef