zynq: Move CONFIG_SYS_SDRAM_SIZE to pre-board configs

CONFIG_SYS_SDRAM_SIZE is specific to a board hence moved
to specific pre-config board files.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
diff --git a/include/configs/zynq_zc70x.h b/include/configs/zynq_zc70x.h
index 9910804..6950d41 100644
--- a/include/configs/zynq_zc70x.h
+++ b/include/configs/zynq_zc70x.h
@@ -10,6 +10,8 @@
 #ifndef __CONFIG_ZYNQ_ZC70X_H
 #define __CONFIG_ZYNQ_ZC70X_H
 
+#define CONFIG_SYS_SDRAM_SIZE		(1024 * 1024 * 1024)
+
 #define CONFIG_ZYNQ_SERIAL_UART1
 #define CONFIG_ZYNQ_GEM0
 #define CONFIG_ZYNQ_GEM_PHY_ADDR0	7