Support BF16 model

Author: wine99

ggml/src/ggml-openvino/ggml-decoder.cpp

@@ -419,8 +419,14 @@ std::map<std::string, std::shared_ptr<ov::Node>> GgmlOvDecoder::create_weight_no
 
 std::shared_ptr<ov::Node> GgmlOvDecoder::create_weight_node(ggml_tensor* tensor,
                                                             std::optional<ExtraQuantType> requant_type) {
-    std::set<ggml_type> weight_types = {
-        GGML_TYPE_F32, GGML_TYPE_F16, GGML_TYPE_Q8_0, GGML_TYPE_Q4_0, GGML_TYPE_Q4_1, GGML_TYPE_Q4_K, GGML_TYPE_Q6_K};
+    std::set<ggml_type> weight_types = {GGML_TYPE_F32,
+                                        GGML_TYPE_F16,
+                                        GGML_TYPE_BF16,
+                                        GGML_TYPE_Q8_0,
+                                        GGML_TYPE_Q4_0,
+                                        GGML_TYPE_Q4_1,
+                                        GGML_TYPE_Q4_K,
+                                        GGML_TYPE_Q6_K};
     if (weight_types.find(tensor->type) == weight_types.end()) {
         throw std::runtime_error("Unexpected weight tensor type: " + std::string(tensor->name) + " with type " +
                                  ggml_type_name(tensor->type));

ggml/src/ggml-openvino/utils.cpp

@@ -276,6 +276,7 @@ std::map<ggml_type, ExtraQuantType> get_types_to_requant(const std::string& devi
             {GGML_TYPE_Q6_K, ExtraQuantType::Q8_1_C},
         };
     }
+    return {};
 }
 
 ov::AnyMap get_npu_generate_config() {