cmake: don't run crosstool-version-check for clang
cmake: don't run crosstool-version-check for clang

We will likely need to check clang version as well, eventually.
However at the moment clang builds change too often for such check
to be maintainable. Disable it for clang.

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf