Revert "FQ output data type copied from 3,4 input data type (#4341)" (#4378)

This reverts commit 35d50450.

src/ngraph/op/fused/fake_quantize.cpp

@@ -77,18 +77,7 @@ void op::FakeQuantize::validate_and_infer_types()
             NODE_VALIDATION_CHECK(this, false, "Unsupported auto broadcast specification");
         }
     }
-
-    element::Type result_et;
-    NODE_VALIDATION_CHECK(
-        this,
-        element::Type::merge(result_et, get_input_element_type(3), get_input_element_type(4)),
-        "Arguments do not have the same element type (arg3 element type: ",
-        get_input_element_type(3),
-        ", arg4 element type: ",
-        get_input_element_type(4),
-        ").");
-
-    set_output_type(0, result_et, get_input_partial_shape(0));
+    set_output_type(0, get_input_element_type(0), get_input_partial_shape(0));
 }
 
 NodeVector op::FakeQuantize::decompose_op() const