drm/xe/pvc: Force even num engines to use 64B

Wa_16017236439 requires that we update BCS_SWCTRL
(via indirect context batch buffer) to set 64B
transfers when running on an even-numbered BCS
engine and 256B on an odd-numbered BCS engine.

v2: Move WA from engine_was[] to lrc_was[]

Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay@intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>