fdt: Add function to read boolean property

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Commit-Ready: Gabe Black <gabeblack@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/fdtdec.h b/include/fdtdec.h
index f8a4e94..a37cf54 100644
--- a/include/fdtdec.h
+++ b/include/fdtdec.h
@@ -399,6 +399,16 @@
 		int default_val);
 
 /**
+ * Look in the FDT for a config item with the given name
+ * and return whether it exists.
+ *
+ * @param blob		FDT blob
+ * @param prop_name	property name to look up
+ * @return 1, if it exists, or 0 if not
+ */
+int fdtdec_get_config_bool(const void *blob, const char *prop_name);
+
+/**
  * Look in the FDT for a config item with the given name and return its value
  * as a string.
  *