ARM: uniphier: remove commented out define

This TODO is no longer useful.  CONFIG_SYS_NS16550_SERIAL is just
ignored on DM serial.

If one wants to use the 16550A UART device on the UniPhier Micro
Support Card, it can be enabled by CONFIG_SYS_NS16550 via Kconfig.
Please notice CONFIG_SPL_OF_TRANSLATE must be enabled as well and
the device tree must be treaked in order to use the NS16550 serial
on SPL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

include/configs/uniphier.h

@@ -18,11 +18,6 @@
 #define CONFIG_SYS_NS16550_REG_SIZE	-2
 #endif
 
-/* TODO: move to Kconfig and device tree */
-#if 0
-#define CONFIG_SYS_NS16550_SERIAL
-#endif
-
 #define CONFIG_SMC911X
 
 /* dummy: referenced by examples/standalone/smc911x_eeprom.c */