staging: udlfb: add module options for console and fb_defio

staging: udlfb: add module options for console and fb_defio

Add module options for console and fb_defio

Convert fb_defio on/off switch to module option and add console option.

>From the command line, pass options to modprobe
modprobe udlfb defio=1 console=1

Or for permanent option, create file like /etc/modprobe.d/options with text
options udlfb defio=1 console=1

Accepted options:

fb_defio	Make use of the fb_defio (CONFIG_FB_DEFERRED_IO) kernel
		module to track changed areas of the framebuffer by page faults.
        	Standard fbdev applications that use mmap but that do not
		report damage, may be able to work with this enabled.
		Disabled by default because of overhead and other issues.

console		Allow fbcon to attach to udlfb provided framebuffers. This
		is disabled by default because fbcon will aggressively consume
		the first framebuffer it finds, which isn't usually what the
		user wants in the case of USB displays.

Signed-off-by: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>