global: Move remaining CONFIG_SYS_NS16550_* to CFG_SYS_NS16550_*

The rest of the unmigrated CONFIG symbols in the CONFIG_SYS_NS16550
namespace do not easily transition to Kconfig. In many cases they likely
should come from the device tree instead. Move these out of CONFIG
namespace and in to CFG namespace.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/ls1021atsn.h b/include/configs/ls1021atsn.h
index 8c43f65..1e2db12 100644
--- a/include/configs/ls1021atsn.h
+++ b/include/configs/ls1021atsn.h
@@ -60,7 +60,7 @@
 #define CONFIG_SYS_SDRAM_BASE		CONFIG_SYS_DDR_SDRAM_BASE
 
 /* Serial Port */
-#define CONFIG_SYS_NS16550_CLK		get_serial_clock()
+#define CFG_SYS_NS16550_CLK		get_serial_clock()
 
 /* I2C */