part: Add a fallback for part_get_bootable()

This function can be called when partition support is disabled. Add a
static inline to handle this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/part.h b/include/part.h
index 16ba8c1..f321479 100644
--- a/include/part.h
+++ b/include/part.h
@@ -372,14 +372,6 @@
 }
 #endif
 
-/**
- * part_get_bootable() - Find the first bootable partition
- *
- * @desc: Block-device descriptor
- * @return first bootable partition, or 0 if there is none
- */
-int part_get_bootable(struct blk_desc *desc);
-
 struct udevice;
 /**
  * disk_blk_read() - read blocks from a disk partition
@@ -670,12 +662,24 @@
  */
 int part_get_type_by_name(const char *name);
 
+/**
+ * part_get_bootable() - Find the first bootable partition
+ *
+ * @desc: Block-device descriptor
+ * @return first bootable partition, or 0 if there is none
+ */
+int part_get_bootable(struct blk_desc *desc);
+
 #else
 static inline int part_driver_get_count(void)
 { return 0; }
 
 static inline struct part_driver *part_driver_get_first(void)
 { return NULL; }
+
+static inline bool part_get_bootable(struct blk_desc *desc)
+{ return false; }
+
 #endif /* CONFIG_PARTITIONS */
 
 #endif /* _PART_H */