Tagging asahi-6.18.4-1

- initial rebase onto v6.18.x
- Switch to upstream USB Type-C implementation (code is in linux-next),
  fixups and device tree changes are sent
- DCP cleanups, fixes and improvements
  - ARGB2101010 support
  - YCbCr support
  - fixed suspend/resume for Macbook Pro HDMI output
  - 120Hz mode for 14/16-inch Macbook Pros
  - consolidated all drivers in single appledrm module
  - refactor kms plane / dcp surface handling
  - relaxed locking for internal backlight control
  - removed hacks for DP only atc phy mode to drive the HDMI output of
    14/16-inch Macbook Pros
- rebase on newer gem-shmem rust abstractions
- switched gpuvm single-page/repeat support to panthor patches
- aop: prepartions for als support