mx6sxsabresd: Avoid hardcoded RAM size

Instead of passing the total RAM size via PHYS_SDRAM_SIZE option,
we should better use imx_ddr_size() function, which automatically
determines the RAM size.

Signed-off-by: Vanessa Maegima <vanessa.maegima@nxp.com>

board/freescale/mx6sxsabresd/mx6sxsabresd.c

@@ -64,7 +64,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 int dram_init(void)
 {
-	gd->ram_size = PHYS_SDRAM_SIZE;
+	gd->ram_size = imx_ddr_size();
 
 	return 0;
 }

include/configs/mx6sxsabresd.h

@@ -132,7 +132,6 @@
 /* Physical Memory Map */
 #define CONFIG_NR_DRAM_BANKS		1
 #define PHYS_SDRAM			MMDC0_ARB_BASE_ADDR
-#define PHYS_SDRAM_SIZE			SZ_1G
 
 #define CONFIG_SYS_SDRAM_BASE		PHYS_SDRAM
 #define CONFIG_SYS_INIT_RAM_ADDR	IRAM_BASE_ADDR