linux-imx

bpftool: Allow to add compiler flags via EXTRA_CFLAGS variable

Adding EXTRA_CFLAGS allowing user to specify extra flags
for CFLAGS variable.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>