doc: xed from pin
doc: xed from pin

Added a sentence saying where to find the XED include and lib directories in
a PIN distribution.

Change-Id: I1fc5de20d5ac2a5db9503e83a9e5dc40f7402931
Signed-off-by: Markus Metzger <5f675b2b36595f90898e014b548ff7d9bbff2ab7@intel.com>

andikleen/processor-trace,breadbaconic/processor-trace,01org/processor-trace,shadown/processor-trace,hoangt/processor-trace,hoangt/processor-trace,pombreda/processor-trace,drupalhunter-team/processor-trace,01org/processor-trace,breadbaconic/processor-trace,andikleen/processor-trace,shadown/processor-trace,drupalhunter-team/processor-trace,pombreda/processor-trace,01org/processor-trace