gpu: vivante: fix anti-aliasing

Re-disable Z-compression for the specific GPU in the GCW zero,
as it messes with MSAA.
gpu: vivante: replace gckOS_Get(Thread|ProcessID)

Just use linux's own functions task_tgid_vnr and task_pid_vnr.
gpu: vivante: replace gckOS_GetPageSize with PAGE_SIZE

No function is needed for this on Linux.
Also remove (misnamed) pageSize field on gckOS_Command structure,
and add a define COMMAND_QUEUE_SIZE instead.
gpu: vivante: replace gckOS_CopyFromUserData with direct copy_from_user
gpu: vivante: replace gckOS_CopyToUserData with copy_to_user
gpu: vivante: make sure status is initialized in gckKERNEL_OpenUserData
gpu: vivante: replace gckOS_QueryNeedCopy with NO_USER_DIRECT_ACCESS_FROM_KERNEL

Use macro directly, it is defined everywhere. No need for query function.