sdhci-pltfm: add support for CNS3xxx SoC devices

There's nothing special, just SoC-specific ops and quirks.

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Cc: Ben Dooks <ben@simtec.co.uk>
Cc: Richard R?jfors <richard.rojfors@pelagicore.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>