i2c/eeprom: Always define I2C_RXTX_LEN

I2C_RXTX_LEN from include/i2c.h is not defined if CONFIG_DM_I2C is
enabled. This leads to a compilation error on boards that enable both
CONFIG_CMD_EEPROM and CONFIG_DM_I2C.

To avoid this, we define I2C_RXTX_LEN in cmd/eeprom.c if it is not
already defined.

Signed-off-by: Mario Six <mario.six@gdsys.cc>

cmd/eeprom.c

@@ -37,6 +37,10 @@
 #define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS	8
 #endif
 
+#ifndef	I2C_RXTX_LEN
+#define I2C_RXTX_LEN	128
+#endif
+
 #define	EEPROM_PAGE_SIZE	(1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
 #define	EEPROM_PAGE_OFFSET(x)	((x) & (EEPROM_PAGE_SIZE - 1))