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/tec-ng_defconfig b/configs/tec-ng_defconfig
index 7a8d687..5b71327 100644
--- a/configs/tec-ng_defconfig
+++ b/configs/tec-ng_defconfig
@@ -13,6 +13,7 @@
 # CONFIG_CMD_SETEXPR is not set
 # CONFIG_CMD_NFS is not set
 CONFIG_SPI_FLASH=y
+CONFIG_SYS_NS16550=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_USE_PRIVATE_LIBGCC=y