i2c: s3c24x0: fix the compiler error for exynos4

If CONFIG_SYS_I2C_S3C24X0_SLAVE isn't defined, then complie error should
be occurred.
This patch is for preventing it.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/i2c/s3c24x0_i2c.c

@@ -24,6 +24,12 @@
 #include <i2c.h>
 #include "s3c24x0_i2c.h"
 
+#ifndef CONFIG_SYS_I2C_S3C24X0_SLAVE
+#define SYS_I2C_S3C24X0_SLAVE_ADDR	0
+#else
+#define SYS_I2C_S3C24X0_SLAVE_ADDR	CONFIG_SYS_I2C_S3C24X0_SLAVE
+#endif
+
 DECLARE_GLOBAL_DATA_PTR;
 
 /*
@@ -87,7 +93,7 @@ static int s3c24x0_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
 	i2c_bus->clock_frequency = speed;
 
 	i2c_ch_init(i2c_bus->regs, i2c_bus->clock_frequency,
-		    CONFIG_SYS_I2C_S3C24X0_SLAVE);
+		    SYS_I2C_S3C24X0_SLAVE_ADDR);
 
 	return 0;
 }