feat(plat/mediatek/mt8186): add reboot function for PSCI

Add system_reset function in PSCI operations.

TEST=build pass
BUG=b:202871018

Signed-off-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Change-Id: I41001484f6244bd6ae7dedcfb6ce71cd6c035a1e
1 file changed