sx1509: Convert code to use generic i2c bus support

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/example-extras.cfg

@@ -939,11 +939,14 @@
 # prefix. Each expander provides a set of 16 pins (sx1509_my_sx1509:PIN_0 to
 # sx1509_my_sx1509:PIN_15) which can be used in the printer configuration.
 #[sx1509 my_sx1509]
-#address:
+#i2c_mcu: mcu
+#   The name of the micro-controller that the SX1509 chip is connected
+#   to. The default is "mcu".
+#i2c_address:
 #   I2C address used by this expander. Depending on the hardware jumpers
-#   this is one out of the following addresses: 0x3E 0x3F 0x70 0x71. This
-#   parameter must be provided
-#bus: 0
+#   this is one out of the following addresses: 62 63 112 113. This
+#   parameter must be provided.
+#i2c_bus: 0
 #   If the I2C implementation of your microcontroller supports multiple I2C
 #   busses, you may specify the bus number here. The default is 0.
 

config/generic-duet2.cfg

@@ -39,7 +39,7 @@
 # | FAN8 |  sx1509_duex:PIN_15*  |
 # Pins marked with (*) assume the following sx1509 config section:
 #[sx1509 duex]
-#address: 0x3E
+#i2c_address: 62
 #
 ## Heaters and Thermistors
 # | Extruder Drive |  HEAT pin |  TEMP pin |
@@ -324,7 +324,7 @@ serial: /dev/ttyACM0
 restart_method: command
 
 [sx1509 duex]
-address: 0x3E # Address is fixed on duex boards
+i2c_address: 62 # Address is fixed on duex boards
 
 [printer]
 kinematics: cartesian