Update for I2C BusDevice read/write rename.

Author: tannewt

adafruit_pcf8523.py

@@ -103,8 +103,8 @@ def __init__(self, i2c):
         buf = bytearray(2)
         buf[0] = 0x12
         with self.i2c_device as i2c:
-            i2c.writeto(buf, end=1, stop=False)
-            i2c.readfrom_into(buf, start=1)
+            i2c.write(buf, end=1, stop=False)
+            i2c.read_into(buf, start=1)
 
         if (buf[1] & 0b00000111) != 0b00000111:
             raise ValueError("Unable to find PCF8523 at i2c address 0x68.")