wic: Add SD/MMC-Cards support to '--ondisk' param

The special case when wic is set up to use SD/MMC-Cards in place
of sdX disks is not handled properly.

Append 'p' to the rootdev when disk is SD/MMC-Cards fix this situation.

(From OE-Core rev: 3a95c4549f743aa47456c76e687a863c64c7a7f4)

Signed-off-by: João Henrique Ferreira de Freitas <joaohf@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/lib/mic/imager/direct.py

@@ -345,10 +345,14 @@ class DirectImageCreator(BaseImageCreator):
         parts = self._get_parts()
         for num, p in enumerate(parts, 1):
             if p.mountpoint == "/":
+                part = ''
+                if p.disk.startswith('mmcblk'):
+                    part = 'p'
+
                 if self._ptable_format == 'msdos' and num > 3:
-                    rootdev = "/dev/%s%-d" % (p.disk, num + 1)
+                    rootdev = "/dev/%s%s%-d" % (p.disk, part, num + 1)
                 else:
-                    rootdev = "/dev/%s%-d" % (p.disk, num)
+                    rootdev = "/dev/%s%s%-d" % (p.disk, part, num)
                 root_part_uuid = p.part_type
 
         return (rootdev, root_part_uuid)