mmc-twl4030 gpios for all controllers

More HSMMC gpio updates: make the card detect and write protect
handling behave for slots connected to any controller (not just
for MMC1), and for non-twl4030 GPIOs.

It packs some structs more efficiently, and updates mmc platform
data to remember the relevant GPIOs.  It also adds some error
checks.

This removes debouncing, so it goes along with a following patch
to change how twl4030 debouncing kicks in.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>