Ricoh 1180:e823 does not recognize certain types of SD/MMC cards,
as reported at http://launchpad.net/bugs/773524.  Lowering the SD
base clock frequency from 200Mhz to 50Mhz fixes this issue. This
solution was suggest by Koji Matsumuro, Ricoh Company, Ltd.

This change has no negative performance effect on standard SD
cards, though it's quite possible that there will be one on
UHS-1 cards.
Signed-off-by: Manoj Iyer <manoj.iyer@canonical.com>
Tested-by: Daniel Manrique <daniel.manrique@canonical.com>
Cc: Koji Matsumuro <matsumur@nts.ricoh.co.jp>
Cc: <stable@kernel.org>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Chris Ball <cjb@laptop.org>