Merge pull request #629 from ljerry/tf_issue_398

Bring IO storage dummy driver

diff --cc include/drivers/io/io_storage.h
index 243f6883e97644efc63e0f8142f034230bfa616c,f7e5b8652a9d4f28f167c8d5b93008374bca9282..1b3028ae42fbfa007f774c1d2d1740017c57d563
--- 1/include/drivers/io/io_storage.h
--- 2/include/drivers/io/io_storage.h
+++ b/include/drivers/io/io_storage.h
@@@ -43,8 -43,8 +43,9 @@@ typedef enum 
        IO_TYPE_INVALID,
        IO_TYPE_SEMIHOSTING,
        IO_TYPE_MEMMAP,
+       IO_TYPE_DUMMY,
        IO_TYPE_FIRMWARE_IMAGE_PACKAGE,
 +      IO_TYPE_BLOCK,
        IO_TYPE_MAX
  } io_type_t;