video: edid.c: fix "no previous prototype" warning ...

The patch fixes this compiler's warning:

drivers/video/edid.c:390:5: warning: no previous prototype
        for 'fb_get_mode' [-Wmissing-prototypes]
 int fb_get_mode(int flags, u32 val, struct fb_videomode *var)
     ^

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

video/edid: Fix edid_to_display_timings error path ...

edid_to_display_timings is called in drivers/video/imx-ipu-v3/imx-hdmi.c,
drivers/video/simple-panel.c, and drivers/video/edid.c with the struct
display_timings *timings parameter pointing to an embedded struct
display_timings inside a struct fb_info. The timings pointer is not to
be freed in the error path.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

video/edid: Move int_sqrt() out ...

Move int_sqrt() out of drivers/video/edid.c so that it is availible to
other parts of Barebox.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

video: Add edid support ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>