cmake: remove asm macro for clang
cmake: remove asm macro for clang

We're not using inline assembly, anymore.  No need to turn asm into __asm__ for
clang.  Remove it.

Change-Id: I9bb7a73b062a10815ad819ab452125119306219c
Signed-off-by: Markus Metzger <5f675b2b36595f90898e014b548ff7d9bbff2ab7@intel.com>

01org/processor-trace,01org/processor-trace,01org/processor-trace