ASoC: rockchip: add missing module.h include

Missing module.h in linux directory will cause compile error with randconfig,
like as:
sound/soc/rockchip/rockchip_i2s.c:526:20: error: expected declaration
specifiers or ‘...’ before string constant
MODULE_DESCRIPTION("ROCKCHIP IIS ASoC Interface");
Signed-off-by: xujianqun <xjq@rock-chips.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

sound/soc/rockchip/rockchip_i2s.c

@@ -10,6 +10,7 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/of_gpio.h>
 #include <linux/clk.h>