msm: timer: don't log timer reads in the rtb

Reads to the timer tend to quickly fill up the rtb, pushing out
other useful information. We can safely assume that the system is
contantly reading the timer registers, and so we don't need to log
this each time.

Change-Id: I2324db32149cbf1b1e6874c17c79221451e995ec
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>