egl: fbdev: remove invalid assert statement

Signed-off-by: Simon Busch <morphis@gravedo.de>
egl: common: add trace statements for reference counting

Signed-off-by: Simon Busch <morphis@gravedo.de>
egl: common: add method to unregister a buffer from gralloc

Signed-off-by: Simon Busch <morphis@gravedo.de>