coresight: add the fuse check logic for coresight etm

Reintroduce the fuse check for ETM as accessing the registers of ETM
when the CPU is offline during the bootup cause the external abort.

Change-Id: Ic4730500e860b0eff445354b8b20171b6e46431b
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>