fb: move and rename extern declaration for global_mode_option

Move the extern declaration for global_mode_option to <linux/fb.h> and rename
the variable to fb_mode_option.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 6729272..58c57a3 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -1056,6 +1056,7 @@
 	u32 flag;
 };
 
+extern const char *fb_mode_option;
 extern const struct fb_videomode vesa_modes[];
 
 struct fb_modelist {