gendoc infra: cosmetic fixes

- wrap lines to 80 characters
- fix space/tab mixup

Signed-off-by: Samuel Martin <s.martin49@gmail.com>
Acked-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
[yann.morin.1998@free.fr: tested all but PDF]
Tested-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>