fbdev: Remove FBINFO_DEFAULT from framebuffer_alloc()'ed structs

The flag FBINFO_DEFAULT is 0 and has no effect, as struct fbinfo.flags
has been allocated to zero by framebuffer_alloc(). 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>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ferenc Bakonyi <fero@drama.obuda.kando.hu>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Maik Broemme <mbroemme@libmpq.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Kristoffer Ericson <kristoffer.ericson@gmail.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Steve Glendinning <steve.glendinning@shawell.net>
Cc: Bernie Thompson <bernie@plugable.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230715185343.7193-6-tzimmermann@suse.de