MMC fixes for 3.5-rc7:
 - Revert a patch that made failing to select power class fatal;
   it turns out that it fails non-fatally on Tegra boards.
   Regression against 3.5-rc1.
 - Add the IRQF_ONESHOT flag to the cd-gpio driver, which turned
   into a regression in 3.5-rc1 when IRQF_ONESHOT became required
   for threaded IRQs with no handler.