AP_IOMCU: fixed DSM bind

libraries/AP_IOMCU/AP_IOMCU.cpp

@@ -795,7 +795,7 @@ void AP_IOMCU::bind_dsm(uint8_t mode)
         return;
     }
     uint16_t reg = mode;
-    write_registers(PAGE_SETUP, PAGE_REG_SETUP_DSM_BIND, &reg);
+    write_registers(PAGE_SETUP, PAGE_REG_SETUP_DSM_BIND, 1, &reg);
 }
 
 /*

libraries/AP_IOMCU/iofirmware/ioprotocol.h

@@ -78,6 +78,7 @@ enum iopage {
 #define PAGE_REG_SETUP_SBUS_RATE    19
 #define PAGE_REG_SETUP_IGNORE_SAFETY 20 /* bitmask of surfaces to ignore the safety status */
 #define PAGE_REG_SETUP_HEATER_DUTY_CYCLE 21
+#define PAGE_REG_SETUP_DSM_BIND     22
 
 // config page registers
 #define PAGE_CONFIG_PROTOCOL_VERSION 0