egl_texture_blit() blits a texture, simliar to egl_fb_blit() but by
rendering the texture to the screen instead of using a framebuffer blit.

egl_texture_blend() renders a texture with alpha blending, will be used
to render the cursor to the screen.
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 20171010135453.6704-6-kraxel@redhat.com