egl: inline eglSwapInterval() fallback

It's literally just a `return EGL_TRUE`, there's no need to have
a function for that.

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6153>
3 files changed