Correct SPL uses of ENV_VARS_UBOOT_RUNTIME_CONFIG

This converts 4 usages of this option to the non-SPL form, since there is
no SPL_ENV_VARS_UBOOT_RUNTIME_CONFIG defined in Kconfig

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/board/xilinx/zynq/board.c b/board/xilinx/zynq/board.c
index df4c457..9a59445 100644
--- a/board/xilinx/zynq/board.c
+++ b/board/xilinx/zynq/board.c
@@ -55,7 +55,7 @@
 		return 0;
 	}
 
-	if (!CONFIG_IS_ENABLED(ENV_VARS_UBOOT_RUNTIME_CONFIG))
+	if (!IS_ENABLED(CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG))
 		return 0;
 
 	switch ((zynq_slcr_get_boot_mode()) & ZYNQ_BM_MASK) {