Here is the fix you need for the missing functions:
	fbpoll, bw2poll, cg2poll, cg4poll
I prefer to fix the problem in conf.c rather than adding a
do-nothing wrapper to every frame-buffer driver.

*** sun3/conf.c.orig	Tue Oct 15 13:02:16 1996
--- sun3/conf.c	Sun Oct 20 21:55:53 1996
***************
*** 145,156 ****
--- 145,163 ----
  cdev_decl(ptc);
  
  /* frame-buffer devices */
+ #define fbpoll seltrue
  cdev_decl(fb);
+ 
  #include "bwtwo.h"
+ #define bw2poll seltrue
  cdev_decl(bw2);
+ 
  #include "cgtwo.h"
+ #define cg2poll seltrue
  cdev_decl(cg2);
+ 
  #include "cgfour.h"
+ #define cg4poll seltrue
  cdev_decl(cg4);
  
  cdev_decl(log);