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/adp-ag101p_defconfig b/configs/adp-ag101p_defconfig
index 4216cd7..87be263 100644
--- a/configs/adp-ag101p_defconfig
+++ b/configs/adp-ag101p_defconfig
@@ -2,3 +2,4 @@
 CONFIG_TARGET_ADP_AG101P=y
 CONFIG_SYS_PROMPT="NDS32 # "
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_SYS_NS16550=y