lib: Add gem_bo_busy

Move gem_bo_busy() from gem_wait_render_timeout.c to lib.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

lib/drmtest.h

@@ -87,6 +87,8 @@ uint32_t gem_context_create(int fd);
 
 void gem_sw_finish(int fd, uint32_t handle);
 
+bool gem_bo_busy(int fd, uint32_t handle);
+
 /* feature test helpers */
 bool gem_uses_aliasing_ppgtt(int fd);
 int gem_available_fences(int fd);