Revert "mmc: sdhci-msm: skip eMMC slot probe if eMMC isn't a bootdevice"

A proxy vote is kept for all the resources binded in the device tree
and those resources would be enabled till the actual driver comes in
and binds to it.

For example every device that needs a clock or have binding for clock in
the device tree all those clocks would be left enabled because of the
proxy vote.

That proxy vote would be removed in the late init when the sync-state
is successful.

For the sync-state to be successful every driver which have bindings
toward that resource must complete the bind with that resource or probe
successfully.

So here for the gcc sync-state to be successful and proxy vote to be
removed every gcc consumer (in this case eMMC) must not bail out and
complete its probe. 

This reverts commit 5827a3e5.

Change-Id: Ic6017ca80a051f6210c9bb1b7f4d27ca842a6f45
Signed-off-by: Sarthak Garg <sartgarg@codeaurora.org>