spl: Use SYS_MALLOC_F instead of SYS_MALLOC_F_LEN

Use the new SPL/TPL/VPL_SYS_MALLOC_F symbols to determine whether the
malloc pool exists.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/arch/arm/lib/bdinfo.c b/arch/arm/lib/bdinfo.c
index 5e6eaad..b88b01e 100644
--- a/arch/arm/lib/bdinfo.c
+++ b/arch/arm/lib/bdinfo.c
@@ -57,7 +57,7 @@
 #ifdef CONFIG_BOARD_TYPES
 	printf("Board Type  = %ld\n", gd->board_type);
 #endif
-#if CONFIG_VAL(SYS_MALLOC_F_LEN)
+#if CONFIG_IS_ENABLED(SYS_MALLOC_F)
 	printf("Early malloc usage: %lx / %x\n", gd->malloc_ptr,
 	       CONFIG_VAL(SYS_MALLOC_F_LEN));
 #endif