feat(plat/mediatek/mt8186): initialize GIC

Initialize GIC for mt8186.

TEST=build pass
BUG=b:202871018

Signed-off-by: Christine Zhu <christine.zhu@mediatek.corp-partner.google.com>
Change-Id: I8d029983c7ce48fa116fafa7fa78c65349308014
3 files changed