[Frontend][ArgParse] Compile with default target(LLVM) when built US…

…E_MRVL=ON(apache#17454)

    This is a use-case of invoking TVMC with default target though it is built with MRVL_ON.
    In command line processing, validate_target_args checks if there are add-on options
    derived from the default arguments of codegen/BYOC and it expects that particular codegen
    to be given explicitly in command line. However, certain codegen's can have default target alone,
    in that case codegen optios are not extracted there by relaxing the validation

Signed-off-by: M N Ganesan <[email protected]>

python/tvm/driver/tvmc/target.py

@@ -186,12 +186,6 @@ def validate_targets(parse_targets, additional_target_options=None):
     if additional_target_options is not None:
         for target_name in additional_target_options:
             if not any([target for target in parse_targets if target["name"] == target_name]):
-                # When built with USE_MRVL=ON, add-on target options are passed from MRVL codegen's
-                # config which has pass_default=True and compiled with default target, don't error
-                # Use case: --target="llvm" cnn.onnx
-                if (len(tvm_targets) == 1) and (target_name == "mrvl"):
-                    return
-
                 first_option = list(additional_target_options[target_name].keys())[0]
                 raise TVMCException(
                     f"Passed --target-{target_name}-{first_option}"