build failure when using NXP imx vivante libraries
Building weston with NXP imx vivante GPU libraries the build fails.
In file included from host/aarch64-buildroot-linux-gnu/sysroot/usr/include/EGL/egl.h:39,
from ../libweston/renderer-gl/gl-renderer.h:36,
from ../libweston/backend-drm/drm-gbm.c:42:
host/aarch64-buildroot-linux-gnu/sysroot/usr/include/EGL/eglplatform.h:144:10: fatal error: X11/Xlib.h: No such file or directory
144 | #include <X11/Xlib.h>
This is because the eglplatform.h has condidtional stuff that will be selected by defines coming through the cflags from the egl.pc file.
To fix this issue take the dependencies to egl if available. Thus the required cflags should be added.