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/vct_premium_onenand_small_defconfig b/configs/vct_premium_onenand_small_defconfig
index ac6f422..a3a93b8 100644
--- a/configs/vct_premium_onenand_small_defconfig
+++ b/configs/vct_premium_onenand_small_defconfig
@@ -18,4 +18,5 @@
 # CONFIG_CMD_NET is not set
 # CONFIG_CMD_NFS is not set
 # CONFIG_CMD_MISC is not set
+CONFIG_SYS_NS16550=y
 CONFIG_USE_PRIVATE_LIBGCC=y