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/am437x_sk_evm_defconfig b/configs/am437x_sk_evm_defconfig
index 1a0b518..b349e57 100644
--- a/configs/am437x_sk_evm_defconfig
+++ b/configs/am437x_sk_evm_defconfig
@@ -15,3 +15,4 @@
 CONFIG_DM=y
 CONFIG_DM_MMC=y
 CONFIG_SPI_FLASH=y
+CONFIG_SYS_NS16550=y