eglfs: Disable eglfs when evdev is not present

EGLFS has a hard dependency on evdev, so don't compile it when
evdev is not present.

This also removes the check that disabled EGLFS specifically for QNX.
Since QNX doesn't have evdev, EGLFS will get disabled automatically.

Change-Id: I9fdb364b2eff9b370fa238609a8f98af6ccb7f7b
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

configure

@@ -4743,7 +4743,7 @@ elif [ "$CFG_OPENGL" = "desktop" ]; then
 fi
 
 if [ "$CFG_EGLFS" != "no" ]; then
-    if [ "$CFG_OPENGL" = "es2" ] && [ "$XPLATFORM_QNX" = "no" ]; then
+    if [ "$CFG_OPENGL" = "es2" ] && [ "$CFG_EVDEV" = "yes" ]; then
         CFG_EGLFS="$CFG_EGL"
     else
         CFG_EGLFS="no"