drivers: soc: llcc_perfmon: Add llcc_perfmon support

This is snapshot of the llcc_perfmon driver from msm-4.9
'commit 646e9d10b336 ("drivers: soc: llcc_perfmon: fix debug message
and code style")'
Also updated ktime_t as s64 for msm-4.14.

This LLCC perfmon driver provides Sysfs interfaces for the clients to
monitor the events. Driver support for monitor events from LLCC sub blocks.

Change-Id: Ic711fdbc774d2da1938feff5c0d7888e5cf8495a
Signed-off-by: Avinash Philip <avinashp@codeaurora.org>
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>