Scull family 3.10

This pull request updates all the scull driver variants.

Most of the changes are the same as previously:
 - Makefile. Moving the declaration of LDDINC earlier solves a compile problem.
 - Update the proc filesystem calls. The proc filesystem interface changed in the kernel 3.10.

Other changes are:
 - lddbus: I added an updated attribute member that was previously removed.
 - sbull: Fixed compiler warnings, result of upstream changes in the API.