include/cmake.mk: fix host builds

Signed-off-by: Felix Fietkau <[email protected]>

include/cmake.mk

@@ -8,6 +8,7 @@ endif
 
 CMAKE_BINARY_DIR = $(PKG_BUILD_DIR)$(if $(CMAKE_BINARY_SUBDIR),/$(CMAKE_BINARY_SUBDIR))
 CMAKE_SOURCE_DIR = $(PKG_BUILD_DIR)
+HOST_CMAKE_SOURCE_DIR = $(HOST_BUILD_DIR)
 MAKE_PATH = $(firstword $(CMAKE_BINARY_SUBDIR) .)
 
 ifeq ($(CONFIG_EXTERNAL_TOOLCHAIN),)
@@ -103,6 +104,6 @@ define Host/Configure/Default
 			-DCMAKE_PREFIX_PATH=$(HOST_BUILD_PREFIX) \
 			-DCMAKE_SKIP_RPATH=TRUE  \
 			$(CMAKE_HOST_OPTIONS) \
-		$(CMAKE_SOURCE_DIR) \
+		$(HOST_CMAKE_SOURCE_DIR) \
 	)
 endef