mmc: sdhci-msm: Use internal voltage control

mmc: sdhci-msm: Use internal voltage control

On qcom SD host controllers voltage switching be done after the HW
is ready for it. The HW informs its readiness through power irq.
The voltage switching should happen only then.

Use the internal voltage switching and then control the voltage
switching using power irq.

IO-bus supply of eMMC would be kept always-on. So set the load
for this supply to configure it in LPM when eMMC is suspend state
and in HPM when eMMC is active.

Co-developed-by: Asutosh Das <asutoshd@codeaurora.org>
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>
Co-developed-by: Vijay Viswanath <vviswana@codeaurora.org>
Signed-off-by: Vijay Viswanath <vviswana@codeaurora.org>
Co-developed-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Link: https://lore.kernel.org/r/1592919288-1020-4-git-send-email-vbadigan@codeaurora.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>