include: Use CONFIG_XPL_BUILD instead of CONFIG_SPL_BUILD

Use the new symbol to refer to any 'SPL' build, including TPL and VPL

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/configs/xilinx_zynqmp.h b/include/configs/xilinx_zynqmp.h
index de0db7b..bb0db7c 100644
--- a/include/configs/xilinx_zynqmp.h
+++ b/include/configs/xilinx_zynqmp.h
@@ -183,7 +183,7 @@
 #endif
 
 /* SPL can't handle all huge variables - define just DFU */
-#if defined(CONFIG_SPL_BUILD) && defined(CONFIG_SPL_DFU)
+#if defined(CONFIG_XPL_BUILD) && defined(CONFIG_SPL_DFU)
 #undef CFG_EXTRA_ENV_SETTINGS
 # define CFG_EXTRA_ENV_SETTINGS \
 	"dfu_alt_info_ram=uboot.bin ram 0x8000000 0x1000000;" \