staging: sm750fb: fix build failure

for powerpc-allyesconfig build failed with an error of g_option
undeclared. we will get this error on all architecture if MODULE is
not defined. fixed the declaration of g_option.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sm750fb/sm750.c

@@ -54,9 +54,7 @@ static const char * g_fbmode[] = {NULL,NULL};
 static const char * g_def_fbmode = "800x600-16@60";
 static char * g_settings = NULL;
 static int g_dualview = 0;
-#ifdef MODULE
 static char * g_option = NULL;
-#endif
 
 /* if not use spin_lock,system will die if user load driver
  * and immediatly unload driver frequently (dual)*/