ns16550: move CONFIG_SYS_NS16550 to Kconfig

Move CONFIG_SYS_NS16550 to Kconfig, and run moveconfig.py.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
diff --git a/configs/ib62x0_defconfig b/configs/ib62x0_defconfig
index 19cbfd5..a229f46 100644
--- a/configs/ib62x0_defconfig
+++ b/configs/ib62x0_defconfig
@@ -1,12 +1,13 @@
 CONFIG_ARM=y
 CONFIG_KIRKWOOD=y
 CONFIG_TARGET_IB62X0=y
+CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="ib62x0 => "
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
-# CONFIG_CMD_SETEXPR is not set
-CONFIG_HUSH_PARSER=y
-CONFIG_CMD_DHCP=y
 CONFIG_CMD_NAND=y
-CONFIG_CMD_PING=y
 CONFIG_CMD_USB=y
+# CONFIG_CMD_SETEXPR is not set
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
+CONFIG_SYS_NS16550=y