build: fix weston-info CFLAGS

  CC       clients/weston-info.o
clients/weston-info.c:31:28: fatal error: wayland-client.h: No such file or directory
compilation terminated.
make[1]: *** [clients/weston-info.o] Error 1

Only triggerable if libwayland is only in a custom prefix.

Fix by adding CLIENT_CFLAGS.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
1 file changed