aerofc: Use the additional I2C

This change plus the new FPGA RTL(version 0xC1 or higher) will make
use of the new I2C bus, this new bus will be shared between aerofc_adc
and ll40ls(if connected) and leaving the old bus just to IST8310.

src/drivers/boards/aerofc-v1/board_config.h

@@ -78,7 +78,8 @@
  *
  */
 
-#define PX4_I2C_BUS_EXPANSION	1
+#define PX4_I2C_BUS_EXPANSION   1
+#define PX4_I2C_BUS_EXPANSION1  2
 #define PX4_I2C_BUS_ONBOARD	3
 
 #define PX4_I2C_OBDEV_HMC5883	0x1e