package/mesa3d: virgl driver needs egl & drm

Fixes
http://autobuild.buildroot.net/results/7b3/7b38131ebb6b20daec1a6d2c49b25c5300f319fe/
http://autobuild.buildroot.net/results/61b/61b8b87f0460751257f480ef478e753635cab798/
http://autobuild.buildroot.net/results/971/97154ea0e780623d23b20b6b9fcc5df6190875c9/
http://autobuild.buildroot.net/results/dcf/dcf4e31e6b6eeadc7a2d7c87697f57d699673b9e/
http://autobuild.buildroot.net/results/399/399cca80ada5798decc87bff69a3acc432e8f3d0/
http://autobuild.buildroot.net/results/60f/60f63958b2310e00937c498ddf2a0295ff77683a/



Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>