coresight: tmc: migrate byte counter to new tmc framework

TMC ETR has moved to new way to allocate and read memory.
Change byte counter to use new interface. This patch also
fixes block_size is not correct issue in byte counter.

Change-Id: I842f653cadefacb96eeea0bef9003df3a3331523
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>