bugfix(i2c): reduce speed of I2C master bus reset routine and release SDA

bugfix(i2c): reduce speed of I2C master bus reset routine and release SDA

closes https://github.com/espressif/esp-idf/issues/2494
closes https://github.com/espressif/esp-idf/pull/2493
closes https://github.com/espressif/esp-idf/pull/2496

1. Change bus reset to handle interrupted READ sequences.
2. Slow down I2C to 100khz during reset
3. If a SLAVE device was in a read operation when the bus was interrupted, the SLAVE device is controlling SDA.The only bit during the 9 clock cycles of a byte READ the MASTER(ESP32) is guaranteed control over, is during the ACK bit period.
If the SLAVE is sending a stream of ZERO bytes, it will only release SDA during the ACK bit period. The master(ESP32) cannot generate a STOP unless SDA is HIGH. So, this reset code synchronizes the bit stream with, Either, the ACK bit, Or a 1 bit.