package/glmark2: Wayland-gl support also needs egl

package/glmark2: Wayland-gl support also needs egl

We were missing the egl dependency when enabling Wayland GL support:
https://github.com/glmark2/glmark2/blob/master/src/wscript_build#L28

Fixes
http://autobuild.buildroot.net/results/858/8587d0cea86efa4c6e98817cadc7cce0b1b36e3d/
http://autobuild.buildroot.net/results/1f6/1f6853d5f7a83be60ccdf4f071a1df1491cf8137/
http://autobuild.buildroot.net/results/a4d/a4d830291ee8550b3c544ade7169218d5edd4d52/
http://autobuild.buildroot.net/results/536/536a8dc62783633943770a278dc9f1c6c5c0807c/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>