perf: Fix event creation for task context

During the perf event creation, the perf-core ignores immediate
installation of the events whose cpu is offline. However, this is
only valid for events created in cpu context, but not for task
context. The fix basically moves the check only for the events
meant to be installed in cpu context.

Change-Id: I23ed58955fda5390e476033e776ef9b815a7d923
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>