coresight: ost: Add snapshot of Coresight OST driver

This is a snapshot of the coresight-ost driver as of msm-4.9
commit '449442be82f3eba7b2e0513381cc49b994c97c55'(coresight:
ost: Switch to no log api for STM device writes).

Change-Id: I6c0d9368120c1b0bab9bda1fedfad5702b413a61
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>