x86: minnowmax: Drop the cache line size hack

Now that the RTL8169 driver warning is fixed we can drop this. The incorrect
value is causing problems with USB EHCI.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

include/configs/minnowmax.h

@@ -60,9 +60,6 @@
 #define CONFIG_FIT_SIGNATURE
 #define CONFIG_RSA
 
-/* Avoid a warning in the Realtek Ethernet driver */
-#define CONFIG_SYS_CACHELINE_SIZE 16
-
 #define CONFIG_ENV_SECT_SIZE		0x1000
 #define CONFIG_ENV_OFFSET		0x007fe000