Remove the header search path to the current directory.

The compiler will search headers in the current directory by
using #include "..." instead of #include <...>

Also, change TRACE_INCLUDE_PATH to point to the location of trace.h.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>