[ARM] Fix a pile of broken watchdog drivers

These patches from Adrian fix:
- ixp4xx_wdt: 20d35f3e
  CC      drivers/watchdog/ixp4xx_wdt.o
ixp4xx_wdt.c:32: error: expected '=', ',', ';', 'asm' or '__attribute__'
ixp4xx_wdt.c: In function 'wdt_enable':
ixp4xx_wdt.c:41: error: 'wdt_lock' undeclared (first use in this
ixp4xx_wdt.c:41: error: (Each undeclared identifier is reported only
ixp4xx_wdt.c:41: error: for each function it appears in.)
ixp4xx_wdt.c: In function 'wdt_disable':
ixp4xx_wdt.c:52: error: 'wdt_lock' undeclared (first use in this
ixp4xx_wdt.c: In function 'ixp4xx_wdt_init':
ixp4xx_wdt.c:186: error: 'wdt_lock' undeclared (first use in this
make[3]: *** [drivers/watchdog/ixp4xx_wdt.o] Error 1

- at91rm9200_wdt: 2760600d
  CC      drivers/watchdog/at91rm9200_wdt.o
at91rm9200_wdt.c:188: error: 'at91_wdt_ioctl' undeclared here (not in a
make[3]: *** [drivers/watchdog/at91rm9200_wdt.o] Error 1

- wdt285: d0e58eed
  CC [M]  drivers/watchdog/wdt285.o
wdt285.c: In function 'footbridge_watchdog_init':
wdt285.c:211: error: 'KERN_WARN' undeclared (first use in this function)
wdt285.c:211: error: (Each undeclared identifier is reported only once
wdt285.c:211: error: for each function it appears in.)
wdt285.c:212: error: expected ')' before string constant
make[3]: *** [drivers/watchdog/wdt285.o] Error 1

And this patch from rmk:
- s3c2410_wdt: 41dc8b72
  CC      drivers/watchdog/s3c2410_wdt.o
s3c2410_wdt.c: In function `s3c2410wdt_start':
s3c2410_wdt.c:161: warning: `return' with a value, in function returning void

Reported-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>