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/include/configs/imx8mp_dhcom_pdk2.h b/include/configs/imx8mp_dhcom_pdk2.h
index bf87825..62bcef5 100644
--- a/include/configs/imx8mp_dhcom_pdk2.h
+++ b/include/configs/imx8mp_dhcom_pdk2.h
@@ -14,7 +14,7 @@
 #define CONFIG_SYS_INIT_RAM_ADDR	0x40000000
 #define CONFIG_SYS_INIT_RAM_SIZE	0x200000
 
-#define CONFIG_SYS_SDRAM_BASE		0x40000000
+#define CFG_SYS_SDRAM_BASE		0x40000000
 #define PHYS_SDRAM			0x40000000
 #define PHYS_SDRAM_SIZE			0x20000000 /* Minimum 512 MiB DDR */