mainboard/asus/m5a88-v/devicetree.cb: Fix formatting

Strip incorrect comments pretaining to the superio, and replace spaces
with tabs.

Change-Id: Ib3f6094c552777552d0ec06e3236210ee2e7b05d
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/5562
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>