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/B4420QDS_NAND_defconfig b/configs/B4420QDS_NAND_defconfig
index 986eda6..b415324 100644
--- a/configs/B4420QDS_NAND_defconfig
+++ b/configs/B4420QDS_NAND_defconfig
@@ -6,3 +6,4 @@
 CONFIG_SPI_FLASH=y
 CONFIG_NETDEVICES=y
 CONFIG_E1000=y
+CONFIG_SYS_NS16550=y