AP_InternalError: add dma_fail

libraries/AP_InternalError/AP_InternalError.cpp

@@ -58,6 +58,7 @@ void AP_InternalError::errors_as_string(uint8_t *buffer, const uint16_t len) con
         "imu_reset",  // imu_reset
         "gpio_isr",
         "mem_guard",
+        "dma_fail",
     };
 
     static_assert((1U<<(ARRAY_SIZE(error_bit_descriptions))) == uint32_t(AP_InternalError::error_t::__LAST__), "too few descriptions for bits");

libraries/AP_InternalError/AP_InternalError.h

@@ -64,7 +64,8 @@ public:
         imu_reset                   = (1U << 24),  //0x1000000 16777216
         gpio_isr                    = (1U << 25),  //0x2000000 33554432
         mem_guard                   = (1U << 26),  //0x4000000 67108864
-        __LAST__                    = (1U << 27),  // used only for sanity check
+        dma_fail                    = (1U << 27),  //0x8000000 134217728
+        __LAST__                    = (1U << 28),  // used only for sanity check
     };
 
     // if you've changed __LAST__ to be 32, then you will want to