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/mcx_defconfig b/configs/mcx_defconfig
index 1d82c40..1e204d5 100644
--- a/configs/mcx_defconfig
+++ b/configs/mcx_defconfig
@@ -9,3 +9,4 @@
 # CONFIG_CMD_FPGA is not set
 CONFIG_CMD_GPIO=y
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_SYS_NS16550=y