bitbake.conf/pseudo: Switch from exclusion list to inclusion list

bitbake.conf/pseudo: Switch from exclusion list to inclusion list

Currently, pseudo tracks all files referenced within its presence unless
they're listed in an exclusion list. The exclusion list has grown to be
fairly unwieldy.

This patch swaps PSEUDO_IGNORE_PATHS for PSEUDO_INCLUDE_PATHS which in
theory should be easier and more explicit to maintain.

This change does drop many directories from pseudo coverage including
/home and /tmp. There may be adapatations needed for recipes/classes
using pseudo in specific ways.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>