Two changes to make the tests less susceptible to random failures:
- Free up newlib memory to not have false-positive memory leaks due to
lazy allocations in reent structure
- Reset between tests, so that one failing test doesn't cause
subsequent tests to fail
Both changes are already applied to esp_driver_sdmmc test app.
These tests were disabled since SDMMC_FREQ_HIGHSPEED with sdspi didn't
work on ESP32 and ESP32-S3. However we don't have other tests for
slot 1, meaning that we weren't running probe and perf tests at all.
This commit re-enables the tests, keeping them with SDMMC_FREQ_DEFAULT
