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/yucca_defconfig b/configs/yucca_defconfig
index 6c8e20a..c3e7a7a 100644
--- a/configs/yucca_defconfig
+++ b/configs/yucca_defconfig
@@ -1,3 +1,4 @@
 CONFIG_PPC=y
 CONFIG_4xx=y
 CONFIG_TARGET_YUCCA=y
+CONFIG_SYS_NS16550=y