defconfig: 8974: disable coresight for perf defconfig

Disable CoreSight drivers for perf defconfig to avoid power and
performance penalty. This is also reduce memory utilization.

Disabling CoreSight drivers also results in disabling JTag save
and restore code.

Change-Id: Ia98d730193fa4874d50226cbba07ac45fb831fde
Signed-off-by: Pratik Patel <pratikp@codeaurora.org>