[ARM] 3457/1: i.MX: SD/MMC support for i.MX/MX1

Patch from Pavel Pisa

This patch adds support of i.MX/MX1 SD/MMC controller.
It has been significantly redesigned from the original Sascha Hauer's
version to support scatter-gather DMA, to conform to latest Pierre Ossman's
and Russell King's MMC-SD Linux 2.6.x infrastructure.
The handling of all events has been moved to the softirq context
and is designed with no busy-looping in mind. Unfortunately
some controller bugs has to be overcome by limited looping
about 2-20 usec but these are observed only for initial card
recognition phase.

There are still some missing/missed IRQs problems under heavy load.
Help of somebody with access to the full SDHC design information
is probably necessary.

Regenerated against 2.6.16-git-060402 to solve clash with other patches.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>