dm: core: Allow devres to be disabled in SPL

At present if devres is enabled in U-Boot proper it is enabled in SPL.
We don't normally want it there, so disable it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Angus Ainslie <angus@akkea.ca>
diff --git a/include/dm/devres.h b/include/dm/devres.h
index 0ab277e..697534a 100644
--- a/include/dm/devres.h
+++ b/include/dm/devres.h
@@ -30,7 +30,7 @@
 	int total_size;
 };
 
-#ifdef CONFIG_DEVRES
+#if CONFIG_IS_ENABLED(DEVRES)
 
 #ifdef CONFIG_DEBUG_DEVRES
 void *__devres_alloc(dr_release_t release, size_t size, gfp_t gfp,
@@ -207,7 +207,7 @@
 /* Get basic stats on allocations */
 void devres_get_stats(const struct udevice *dev, struct devres_stats *stats);
 
-#else /* ! CONFIG_DEVRES */
+#else /* ! DEVRES */
 
 static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
 {