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/maltael_defconfig b/configs/maltael_defconfig
index 858a852..d24d217 100644
--- a/configs/maltael_defconfig
+++ b/configs/maltael_defconfig
@@ -6,4 +6,5 @@
 # CONFIG_CMD_FPGA is not set
 # CONFIG_CMD_SETEXPR is not set
 # CONFIG_CMD_NFS is not set
+CONFIG_SYS_NS16550=y
 CONFIG_USE_PRIVATE_LIBGCC=y