Makefile: Suppress few warnings with clang

Enable -Wno-unsequenced option to suppress these warnings on clang
compilation.

Change-Id: Ib6c81b4d489ccc1715e1f0d23833b8463a39f834
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
[snaseem@codeaurora.org: Resolve trivial merge conflict.]
Signed-off-by: Shadab Naseem <snaseem@codeaurora.org>