CHUNK_TYPE_DONT_CARE should skip over the specified number of blocks, but
currently fails to increment the device block address. This results in
filesystem images getting written incorrectly. Add the missing block
address incrementing.

Cc: Steve Rae <srae@broadcom.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Steve Rae <srae@broadcom.com>