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/dockstar_defconfig b/configs/dockstar_defconfig
index 819cf1f..43e6423 100644
--- a/configs/dockstar_defconfig
+++ b/configs/dockstar_defconfig
@@ -5,3 +5,4 @@
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_SYS_NS16550=y