msm: smem_log: sync timestamp source

The remote subsystems that log into the shared memory log have switched to
using the cntpct clock source for timestamps.  Synchronize the timestamps
from Linux processors by using the same clock source instead of simulating
a 32.768KHz clock source.

CRs-Fixed: 473747
Change-Id: I5aab69eaf363198f45a8c88fe2d92d9bfe78a86a
Signed-off-by: Jeffrey Hugo <jhugo@codeaurora.org>