mfd: twl4030-power: Fix pmic for boards that need vmmc1 on reboot

At least two different omap3630/3730 boards booting from MMC1
fail to reboot if the "ti,twl4030-power-idle-osc-off" or
"ti,twl4030-power-idle" compatible flags are set.  This patch will
keep the vmmc1 powered up during reboot allowing the bootloader
to load.

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>