global: Move remaining CONFIG_SYS_SDRAM_* to CFG_SYS_SDRAM_*

The rest of the unmigrated CONFIG symbols in the CONFIG_SYS_SDRAM
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/board/toradex/colibri_imx6/colibri_imx6.c b/board/toradex/colibri_imx6/colibri_imx6.c
index 475250d..65e0e9a 100644
--- a/board/toradex/colibri_imx6/colibri_imx6.c
+++ b/board/toradex/colibri_imx6/colibri_imx6.c
@@ -73,7 +73,7 @@
 int dram_init(void)
 {
 	/* use the DDR controllers configured size */
-	gd->ram_size = get_ram_size((void *)CONFIG_SYS_SDRAM_BASE,
+	gd->ram_size = get_ram_size((void *)CFG_SYS_SDRAM_BASE,
 				    (ulong)imx_ddr_size());
 
 	return 0;