pkg/archlinux: waffle does not link against libegl
pkg/archlinux: waffle does not link against libegl

As such demote libegl to makedepend/optdepent, so that
one can build waffle, and optionally use x11_egl/gbm/wayland.

Signed-off-by: Emil Velikov <4c996f2f093ddd0585a556460b4cc3ba555546ef@gmail.com>
Reviewed-by: Chad Versace <a557f7f75bf28dc19ac99107f5cc7cd6b3fbdb1a@linux.intel.com>

chadversary/waffle,waffle-gl/waffle,waffle-gl/waffle,evelikov/waffle,dcbaker/waffle,evelikov/waffle,dcbaker/waffle,fjhenigman/waffle,fjhenigman/waffle,chadversary/waffle,waffle-gl/waffle,chadversary/waffle,dcbaker/waffle,fjhenigman/waffle,evelikov/waffle,waffle-gl/waffle,maurossi/waffle,maurossi/waffle,maurossi/waffle