coresight: cti: Move CTI DEVID register read from cti_probe

CTI devid register read is currently done in cti_probe. This can
be done dynamically inside sysfs callbacks rather than of reading
from the probe. Also, we must take into to account when accessing
IP's which are in low power state. This patch tries to address both
cases by moving cti devid register read inside sysfs callback and
by using SMP cross calls.

Change-Id: Ic963e21f91e14a17673e77dfef7dc6bab141ee65
Signed-off-by: Yadu MG <ymg@codeaurora.org>