anv: Add support to copy/clear MSAA images over compute queue

The following commit:

anv: Add support for a transfer queue on Alchemist 

is from the MR !18325 (merged).

The following two commits fix some issues and refactor code in order to support the transfer queue:

anv: Return true while initializing copy engine class
anv: Replace is_blitter_queue_cmd_buffer usage with anv_cmd_buffer_is_blitter_queue

Here is the proposal by @llandwerlin to get the MSAA copy/clear working on compute queue: !18325 (comment 1899944)

Thanks to @llandwerlin and @kwg for answering/clearing all the doubts.

**In order to enable async compute queue on DG2, We need GuC firmware version 70.6.2+. Users may choose to update the GuC version manually from https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/ repo. **

We still have the compute queue behind env var INTEL_COMPUTE_CLASS, which can be toggled using that.