arch/xtensa/esp32[-s2|-s3]: add USE_NXTMPDIR_ESP_REPO_DIRECTLY

Directly downloading the Git repository is inconvenient for local debugging.
This will allow to automatically download external packages from the Internet.
If not set, the repo need to be download will need to provide them manually,
otherwise an error will occur and the build will be aborted.

Add `USE_NXTMPDIR_ESP_REPO_DIRECTLY`, with this we can use
`USE_NXTMPDIR_ESP_REPO_DIRECTLY=y make` which can directly use esp-hal-3rdparty
under nxtmpdir without CHECK_COMMITSHA, reset, checkout and update.

Signed-off-by: v-tangmeng <[email protected]>

Author: TangMeng12