cgtqmx6eval: Remove uneeded PHYS_SDRAM_SIZE

cgtqmx6eval uses the imx_ddr_size() function to calculate the DDR size in
runtime, so there is no need to define PHYS_SDRAM_SIZE.

Remove the unneeded definition.

Cc: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Otavio Salvador <otavio@ossystems.com.br>

include/configs/cgtqmx6eval.h

@@ -251,7 +251,6 @@
 /* Physical Memory Map */
 #define CONFIG_NR_DRAM_BANKS	       1
 #define PHYS_SDRAM		       MMDC0_ARB_BASE_ADDR
-#define PHYS_SDRAM_SIZE			       (1u * 1024 * 1024 * 1024)
 
 #define CONFIG_SYS_SDRAM_BASE	       PHYS_SDRAM
 #define CONFIG_SYS_INIT_RAM_ADDR       IRAM_BASE_ADDR