iris: Flush untyped dataport cache when HDC flush is requested on compute

iris: Flush untyped dataport cache when HDC flush is requested on compute

In the Intel(R) Arc(tm) A-Series Graphics and Intel Data Center GPU
Flex Series Open-Source Programmer's Reference Manual, Vol 2a: Command
Reference: Instructions, PIPE_CONTROL, HDC Pipeline Flush (DWord 0,
Bit 9), there is a programming note:

> When the "Pipeline Select" mode is set to "GPGPU", the LSC Untyped
> L1 cache flush is controlled by "Untyped Data-Port Cache Flush" bit
> in the PIPE_CONTROL command.

Ref: bd8e8d204db ("iris: Add missing untyped data port flush on PIPELINE_SELECT")
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23176>