Build is broken without EGL since version 2.0.12 and
https://hg.libsdl.org/SDL/rev/9761858bd6a3:
/home/giuliobenetti/autobuild/run/instance-1/output-1/build/sdl2-2.0.12/src/video/kmsdrm/SDL_kmsdrmvideo.c: In function 'KMSDRM_CreateSurfaces':
/home/giuliobenetti/autobuild/run/instance-1/output-1/build/sdl2-2.0.12/src/video/kmsdrm/SDL_kmsdrmvideo.c:394:5: error: unknown type name 'EGLContext'