lantiq: remove residual watchdog parts from ltq-vmmc

modify 500-ar9_vr9.patch from
commit 29367aac ("lantiq: ltq-vmmc add support for ar9-vr9")

- remove unused dependencies to external watchdog functions
  (wdog setup is already disabled)
- using header file from kernel (asm/vpe.h) instead patched file (vpe.h)
- cleanup whitspace warning

Signed-off-by: Stefan Koch <stefan.koch10@gmail.com>