clocksource: arch_timer: Use _no_log variants while accessing registers

arch_timer register accesses happen more frequently flooding the
RTB logs. Since they are not that useful for debugging purposes,
use _no_log variants while accessing those registers.

Change-Id: Ide35ef1a01e4792c1b3b7b7be7ad3f069dc2f694
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>