glamor: Switch XY bitmap putimage function for small images

Use the glamor_put_image_xy_gl for small images as that is quite a bit
faster.

Signed-off-by: Keith Packard <keithp@keithp.com>
4 jobs for glamor-accelerate-xy in 6 minutes and 9 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Docker Image
passed #2177226
debian-testing

00:00:20

 
  Build And Test
passed #2177227
autotools

00:05:49

passed #2177228
meson

00:01:24

passed #2177229
meson-noglamor

00:01:16