coresight: tgu: Add snapshot of Trigger Generation Unit

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: I5a7d83a32fd5e67e4a379e73a6f8af7168db18fa
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>
Signed-off-by: Mulu He <muluhe@codeaurora.org>