Updates to the mmc-twl4030 code:

 - Partial workaround for the bug fixed more comprehensively
   by f4223ec2 ... workaround
   applies only to MMC devs using this code.

 - Fix a cut'n'paste bug as noted by Adrian Hunter:  the intent
   was to "disable" not (re)"enable".

The reason to want this workaround is lack of faith that any
sane fix for that regulator framework bug will ever merge,
while still wanting to see things work in mainline.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>