fbdev: Remove FBINFO_FLAG_DEFAULT from kzalloc()'ed structs

The flag FBINFO_FLAG_DEFAULT is 0 and has no effect, as struct
fbinfo.flags has been allocated to zero by kzalloc(). So do not
set it.

Flags should signal differences from the default values. After cleaning
up all occurrences of FBINFO_DEFAULT, the token will be removed.

v4:
	* clarify commit message (Geert, Dan)
v2:
	* fix commit message (Miguel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Helge Deller <deller@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-14-tzimmermann@suse.de