gui: blit the surface on demand ...

Do not blit the surface everytime we write an image
As we want to able to render multiple image this will cause 1 blit per image;

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

graphic_utils: introduce common fb_open/close ...

To open, memmap, get the fb_info and if needed allocate the offscreen buffer

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gui: introduce screen and surface to factorize and simplify code ...

Instead of passing hundreds of parameter, just pass the right structure.

struct screen represent the screen with a without double buffering.
struct surface represent the part of the screen we want to render.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

graphic_utils: pass image so we can draw only the visible part of the image ...

This is needed if the image is bigger than the screen.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

gui: move gui file to include/gui and lib/gui ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>