Disable I2CA in all firmware builds

It is unlikely that any future revision of the hardware will use I2CA.

firmware/build.sh

@@ -45,7 +45,7 @@ sdcc \
 	-I. \
 	-DFW_REVISION_STR="\"$(git describe) $(git log -1 --format=%cd --date=iso)\"" \
 	-DCONFIG_STOCK_FW=1 \
-	-DCONFIG_I2C_A=1 \
+	-DCONFIG_I2C_A=0 \
 	build/stock-ivt.rel main.c \
 	-o build/fw-stock.ihx
 

firmware/main.c

@@ -37,7 +37,7 @@
 #define CONFIG_STOCK_FW 1
 #endif
 #ifndef CONFIG_I2C_A
-#define CONFIG_I2C_A 1
+#define CONFIG_I2C_A 0
 #endif
 
 #define USB_DEBUG 0