Patch from Ian Campbell

On PXA255 there is no way to disable the watchdog. Turning off OIER[E3]
as suggested in the existing comment does not work.

I posted a note to the ARM mailing list a little while ago asking for
opinions from people using SA1100. There was one reponse from Nico who
believes that the SA1100 is the same as the PXA255 in this respect.

You also asked me to involve the watchdog maintainer which I tried to
do but didn't hear anything back. There are only a couple of other
drivers which can't stop the watchdog and there seems to be no
consistancy regarding printing an error etc. I decided to print
something since that matches the case for all the other drivers when
NOWAYOUT is turned on.

Also, I changed the device .name to "watchdog" like most of the other
watchdogs. udev uses it as the device name (by default) and spaces etc.
get in the way.

Superceded 2833/1 because 2.6.13-rc4 caused rejects.
Signed-off-by: NIan Campbell <icampbell@arcom.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>