Revert "msm: board-8960: Enable PMIC USB OTG switch over current protection"

This reverts commit 2911ab0c.

This change is being reverted because PMIC 8921 USB OTG OCP has
been found to be unreliable at lower battery voltages.
Therefore, the software interface to enable OCP from the board
file is being removed.

Change-Id: I8630b967d535a6a3e3ad404723d87f852d032810
Signed-off-by: David Collins <collinsd@codeaurora.org>