Disable readonly partitions in mtdparts.

Barebox marks its own mtd partitions as read-only, which
makes it impossible for ginstall to write to them.

To update barebox to not mark its partitions readonly
requires us to write to the readonly partitions...

Change-Id: Ib1da38a79198b38e76c9e4aa74d1530175c1d483
diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
index ddf9ec6..37c2449 100644
--- a/drivers/mtd/cmdlinepart.c
+++ b/drivers/mtd/cmdlinepart.c
@@ -155,7 +155,13 @@
         /* test for options */
         if (strncmp(s, "ro", 2) == 0)
 	{
+#if 0
+		/* It turns out that if you have a bootloader which marks
+		 * its partitions read-only, and you don't want it to do so,
+		 * you have trouble updating it BECAUSE IT IS READONLY.
+		 * <sob>. */
 		mask_flags |= MTD_WRITEABLE;
+#endif
 		s += 2;
         }