Add Hardware Reset when Initing I2C peripheral (espressif#1201)

This change uses the `_RST` bit of the i2c peripheral to force the hardware into power on reset state. The prior code assumed the peripheral was already in a reset, it just cleared the reset bit. Chuck.

Author: stickbreaker

cores/esp32/esp32-hal-i2c.c

@@ -444,11 +444,13 @@ i2c_t * i2cInit(uint8_t i2c_num, uint16_t slave_addr, bool addr_10bit_en)
 #endif
 
 if(i2c_num==0){
+DPORT_SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT0_RST); // I2C0 peripheral into Reset mode
 DPORT_SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG,DPORT_I2C_EXT0_CLK_EN);
-DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT0_RST);
+DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT0_RST);// Release Reset Mode
  } else{
+DPORT_SET_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT1_RST); // I2C1 peripheral into Reset Mode
 DPORT_SET_PERI_REG_MASK(DPORT_PERIP_CLK_EN_REG,DPORT_I2C_EXT1_CLK_EN);
-DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT1_RST);
+DPORT_CLEAR_PERI_REG_MASK(DPORT_PERIP_RST_EN_REG,DPORT_I2C_EXT1_RST);// Release Reset Mode
  }
 
 I2C_MUTEX_LOCK();