fbdev/ep93xx-fb: Do not assign to struct fb_info.dev

Do not assing the Linux device to struct fb_info.dev. The call to
register_framebuffer() initializes the field to the fbdev device.
Drivers should not override its value.

Fixes a bug where the driver incorrectly decreases the hardware
device's reference counter and leaks the fbdev device.

v2:
	* add Fixes tag (Dan)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 88017bda

 ("ep93xx video driver")
Cc: <stable@vger.kernel.org> # v2.6.32+
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230613110953.24176-15-tzimmermann@suse.de