coresight: Remote-etm: Add snapshot of Remote ETM driver

This is a snapshot of the coresight-cti driver as of msm-4.14
commit '7d42028b99d32ad6ec82aa429378fba0280a1c4a'.byte-cntr: Read 64bit rwp
TMC RWP has two 32bit registers which combine to one 64bit register.
Read correct RWP register in byte counter driver.

Change-Id: I0e145d65d0f7155b623e2a79e46fe3ae649a2ee3
Signed-off-by: Mulu He <muluhe@codeaurora.org>