Correct SPL use of CMD_BOOTI

This converts 1 usage of this option to the non-SPL form, since there is
no SPL_CMD_BOOTI defined in Kconfig

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/bootm.c b/boot/bootm.c
index 15fce8a..e6715ae 100644
--- a/boot/bootm.c
+++ b/boot/bootm.c
@@ -226,7 +226,7 @@
 	}
 
 	if (images.os.type == IH_TYPE_KERNEL_NOLOAD) {
-		if (CONFIG_IS_ENABLED(CMD_BOOTI) &&
+		if (IS_ENABLED(CONFIG_CMD_BOOTI) &&
 		    images.os.arch == IH_ARCH_ARM64) {
 			ulong image_addr;
 			ulong image_size;