sdhci-of: add support for the wii sdhci controller

Add support for the Secure Digital Host Controller Interface found on the
"Hollywood" chipset of the Nintendo Wii video game console.

Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>