HACK! mmc: core: Fix power IRQ issues with SDHCI on msm 3.9 kernel

With the new 3.9 kernel there is a change in power up and set IO
voltage sequence due to which the driver waits for an interrupt
that never trigers. Similarly, for eMMC slot, power IRQ will not
be triggered when IO voltage is changed to 1.8V. As a temporary
workaround change the power up sequence and also change the core
layer driver to not issue set voltage request to 1.8V as eMMC will
anyways be set to 1.8V as part of power up by SDHCI driver.

Change-Id: Ibb7c48219b57693c9f3d26b062d18d6d4b6b8b71
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>