ARM64: zynqmp: Move BSS location to the beginning of ram

With SPL_DFU support memory layout needs to be cleanup
that's why move bss to the start of memory.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>

include/configs/xilinx_zynqmp.h

@@ -252,8 +252,8 @@
 #define CONFIG_SPL_MAX_SIZE		0x20000
 
 /* Just random location in OCM */
-#define CONFIG_SPL_BSS_START_ADDR	0x1000000
-#define CONFIG_SPL_BSS_MAX_SIZE		0x2000000
+#define CONFIG_SPL_BSS_START_ADDR	0x0
+#define CONFIG_SPL_BSS_MAX_SIZE		0x80000
 
 #define CONFIG_SPL_FRAMEWORK
 #define CONFIG_SPL_BOARD_INIT