doc/sbe: Fix block indentation
doc/sbe: Fix block indentation

Squash some warnings.

Signed-off-by: Oliver O'Halloran <3dfaff8fa6ae977f042064a112a6aac576279b9b@gmail.com>

qemu/skiboot,open-power/skiboot,qemu/skiboot,shenki/skiboot,shenki/skiboot,open-power/skiboot,qemu/skiboot,open-power/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,qemu/skiboot,shenki/skiboot,legoater/skiboot,legoater/skiboot,shenki/skiboot,qemu/skiboot,open-power/skiboot,open-power/skiboot,legoater/skiboot