memstick: initial commit for Sony MemoryStick support

Sony MemoryStick cards are used in many products manufactured by Sony.
They are available both as storage and as IO expansion cards.  Currently,
only MemoryStick Pro storage cards are supported via TI FlashMedia
MemoryStick interface.

[mboton@gmail.com: biuld fix]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Miguel Boton <mboton@gmail.co>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>