[PATCH] mmc: avoid some resets without card

Some Ricoh controllers only respect a full reset when there is no card in the
slot.  As we wait for the reset to complete, we must avoid even requesting
those resets on the buggy controllers.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>