Gitlab: sage: Add Pine64+ platform

Gitlab: sage: Add Pine64+ platform

This adds the Pine64+ platform to the sage lab, for both legacy and lwIP
networking stacks. In order to build this platform we need to copy
certain files that were built in the container to /tmp and then set
BINMAN_INDIRS to /tmp in order to find them when building.

For now, we disable the test_net_pxe_boot_config test on lwIP as it
leads to a crash that needs to be investigated.

Signed-off-by: Tom Rini <trini@konsulko.com>