gl: fix fallback definition of EGL_DEFAULT_DISPLAY
gl: fix fallback definition of EGL_DEFAULT_DISPLAY

Compiling fbdev backend on RaspberryPi caused the following warning:

compositor-fbdev.c: In function 'fbdev_compositor_create':
compositor-fbdev.c:929:6: warning: passing argument 2 of
'gl_renderer->create' makes integer from pointer without a cast [enabled
by default]
compositor-fbdev.c:929:6: note: expected 'EGLNativeDisplayType' but
argument is of type 'void *'

Fix the definition of EGL_DEFAULT_DISPLAY to match the definition in
EGL/egl.h (of Mesa).

Signed-off-by: Pekka Paalanen <0f6ae7001e34c37b02fb2c1c2573ddf8f442136a@collabora.co.uk>

sir-murray/weston,Fantu/compositor-spice,Fantu/compositor-spice,giucam/weston,jonnylamb/weston,xorgy/weston,jonnylamb/weston,udoprog/weston,krezovic/weston,mchalupa/weston,mchalupa/weston,kwm81/weston,krezovic/weston,Fantu/compositor-spice,eyolfson/weston,Tarnyko/weston-xdg_surface_present,giucam/weston,udoprog/weston,Gnurou/weston,sir-murray/weston,eyolfson/weston,kwm81/weston,xorgy/weston,Tarnyko/weston-xdg_surface_present,Gnurou/weston