Correct SPL uses of LMB

This converts 9 usages of this option to the non-SPL form, since there is
no SPL_LMB defined in Kconfig

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/riscv/lib/bootm.c b/arch/riscv/lib/bootm.c
index f5f8b4c..276677a 100644
--- a/arch/riscv/lib/bootm.c
+++ b/arch/riscv/lib/bootm.c
@@ -64,7 +64,7 @@
 
 static void boot_prep_linux(struct bootm_headers *images)
 {
-	if (CONFIG_IS_ENABLED(OF_LIBFDT) && CONFIG_IS_ENABLED(LMB) && images->ft_len) {
+	if (CONFIG_IS_ENABLED(OF_LIBFDT) && IS_ENABLED(CONFIG_LMB) && images->ft_len) {
 		debug("using: FDT\n");
 		if (image_setup_linux(images)) {
 			printf("FDT creation failed! hanging...");