mips: Always include nanomips disassembler

mips: Always include nanomips disassembler

Since the nanomips disassembler is not C++ code anymore, it need not
depend on link_language == cpp.  Always include it and remove the
CONFIG_NANOMIPS_DIS symbol.

Cc: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20230110084942.299460-1-pbonzini@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>