meta: use require instead of include when file should exist

meta: use require instead of include when file should exist

If the file is expected to exist, then we should always be using require
so that if it doesn't we get an error rather than some other more
obscure failure later on.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>