recipes: Add missing pkgconfig inherit

Various recipes were missing a pkgconfig inherit or pkgconfig-native
dependency despite using pkgconfig.

Add the inherit to igt-gpu-tools/gdb/libmodulemd/libwpe/xwayland/waffle
shaderc/iputils/wpebackend-fdo/lttng-ust/cargo.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>