MFC: r266821 (partial)

- Actually, modules are built correctly when compiled along the kernel as
  they then pick up an opt_global.h from KERNBUILDDIR having PAE defined.
  Thus, build all modules by default except those which still really are
  defective as of r267058.
- Minor style cleanup.

Approved by:	re (glebius)
MFC: r266820 (partial)

- Shrink the list of excluded modules to what actually still doesn't build
  as of r267058.
- Some style cleanups.

Approved by:	re (glebius)