feat(mt8196): add Mediatek EMI stub implementation for mt8196

Implement stub functions for the EMI driver to ensure that the build
can pass when a prebuilt library is not available.

Change-Id: I296945a3df6766a3a133cd385a1e5038ca979403
Signed-off-by: Gavin Liu <gavin.liu@mediatek.corp-partner.google.com>
6 files changed