fbcon: remove restriction on margin color

This removes the restriction on the value range of the fbcon=margin:
parameter. The color value really depends on the driver being used.

Signed-off-by: David Lechner <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
[b.zolnierkie: ported over fbcon changes]
Signed-off-by: Bartlomiej Zolnierkiewicz <[e-mail]>

Documentation/fb/fbcon.txt

···
 	This option specifies the color of the margins. The margins are the
 	leftover area at the right and the bottom of the screen that are not
 	used by text. By default, this area will be black. The 'color' value
-	is 0 to 7 where 0 is black and 7 is white.
+	is an integer number that depends on the framebuffer driver being used.
 
 C. Attaching, Detaching and Unloading
 

drivers/video/fbdev/core/fbcon.c

···
 			options += 7;
 			if (*options)
 				margin_color = simple_strtoul(options, &options, 0);
-			if (margin_color > 7)
-				margin_color = 0;
 			continue;
 		}
 	}