build system: fix NOTFOUND git version error

CMake would fail to find the git version of the IDF repo due to
not being able to parse the whitespace in the git describe command

tools/cmake/build.cmake

@@ -64,7 +64,7 @@ endfunction()
 #
 function(__build_get_idf_git_revision)
     idf_build_get_property(idf_path IDF_PATH)
-    git_describe(idf_ver_git "${idf_path}" "--match v*.*")
+    git_describe(idf_ver_git "${idf_path}" "--match=v*.*")
     if(EXISTS "${idf_path}/version.txt")
         file(STRINGS "${idf_path}/version.txt" idf_ver_t)
         set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS "${idf_path}/version.txt")