linux-postmarketos-mediatek-mt8173: upgrade to 6.11.5

Built locally and tested. Works fine on the c330.

Notes for 6.12 for my future self or other maintainers:

When this series is merged, revert-drm-change.patch can be dropped. Currently un-patched 6.12-rc5 works better than 6.11, but the display has no green color.