powerpc64le: add LINT64LE kernel config

Add configuration file to be used by "FreeBSD-<branch>-powerpc64le-LINT"
CI/Jenkins job

Reviewed by: lwhsu
MFC after: 2 days
Sponsored by: Instituto de Pesquisas Eldorado (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D33136

(cherry picked from commit e671037b3c49734566e7e0af74ba1a64f45b77a2)