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/MPC8308RDB_defconfig b/configs/MPC8308RDB_defconfig
index cb98324..2aec6d9 100644
--- a/configs/MPC8308RDB_defconfig
+++ b/configs/MPC8308RDB_defconfig
@@ -2,3 +2,4 @@
 CONFIG_MPC83xx=y
 CONFIG_TARGET_MPC8308RDB=y
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_SYS_NS16550=y