- Cleanup arch_idle()

- Remove unused external_fault variable in mach-ixp2000/pci.c 
  leftover from older kernel version

- Fix  __setup("ixdp2x01_clock", ixdp2x01_clock_setup) to be 
  "ixdp2x01_clock="
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>