MIPS: Loongson: Add module info to the loongson2_clock driver

This patch fixes a kernel warning when loading the the loongson2_clock
driver:

"Feb 25 23:42:27 localhost kernel: [    4.965000] loongson2_clock: module
license 'unspecified' taints kernel."
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Reported-by: Liu Shiwei <liushiwei@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/1045/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/cpufreq/loongson2_clock.c

@@ -164,3 +164,7 @@ void loongson2_cpu_wait(void)
 	spin_unlock_irqrestore(&loongson2_wait_lock, flags);
 }
 EXPORT_SYMBOL_GPL(loongson2_cpu_wait);
+
+MODULE_AUTHOR("Yanhua <yanh@lemote.com>");
+MODULE_DESCRIPTION("cpufreq driver for Loongson 2F");
+MODULE_LICENSE("GPL");