GL518SM documentation and library support update

* The library can now read GL518SM revision 0x00 voltages (in the worst case,
  it will read zeros if the module was not inserted with readall=1)
* The readall parameter is now documented through MODULE_PARM_DESC
* Note my remarks in the TODO file


git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@403 7894878c-1315-0410-8ee3-d5d059ff63e0

kernel/chips/gl518sm.c

@@ -168,6 +168,9 @@ static int readall = 0;
 extern int init_module(void);
 extern int cleanup_module(void);
 MODULE_PARM(readall,"i");
+MODULE_PARM_DESC(readall,"Enable the experimental code, which tries to find "
+                         "the voltages of revision zero chips by "
+                         "slow (10 seconds) interpolation");
 #endif /* MODULE */
 
 static int gl518_init(void);