While the regulator is indeed powered by the PMIC, basically the whole
system is, and it's always on. Linux doesn't handle this specially
however and will defer SDMMC probe till after the PMIC is probed costing
us some valuable boot time. Fix this up.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>