cmake: modules: generated_file_directories: fix paths

The paths that got assigned to these variable don't quite match
the description, likely a typo, fix that.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>
diff --git a/cmake/modules/generated_file_directories.cmake b/cmake/modules/generated_file_directories.cmake
index aac3b39..9b18e17 100644
--- a/cmake/modules/generated_file_directories.cmake
+++ b/cmake/modules/generated_file_directories.cmake
@@ -19,6 +19,6 @@
 # Optional environment variables:
 # None
 
-set(BINARY_DIR_INCLUDE ${PROJECT_BINARY_DIR}/include/generated)
-set(BINARY_DIR_INCLUDE_GENERATED ${PROJECT_BINARY_DIR}/include/generated)
+set(BINARY_DIR_INCLUDE ${PROJECT_BINARY_DIR}/include)
+set(BINARY_DIR_INCLUDE_GENERATED ${BINARY_DIR_INCLUDE}/generated)
 file(MAKE_DIRECTORY ${BINARY_DIR_INCLUDE_GENERATED})