image: Drop some other #ifdefs in image-board.c

Remove all but a few that are difficult, relying on legacy CONFIG options
or optional global_data fields.

Drop the duplicate function name in the comment for boot_get_cmdline().

Signed-off-by: Simon Glass <sjg@chromium.org>

include/image.h

@@ -360,6 +360,12 @@ typedef struct bootm_headers {
 #endif
 } bootm_headers_t;
 
+#ifdef CONFIG_LMB
+#define images_lmb(_images)	(&(_images)->lmb)
+#else
+#define images_lmb(_images)	NULL
+#endif
+
 extern bootm_headers_t images;
 
 /*