Add support for Secure Digital specific features in the wbsd driver.  Adds
support for read-only switch and wide bus transfers.
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>