enable ShortImplicitPayloadHeader on PVC

Compute workloads add following implicit arguments:
 * payloadHeader - 8 x i32 packing global_id_offset (3 x i32),
   local_size (3 x i32) and 2 x i32 reserved.
 * enqueued_local_size - 3 x i32
Most of the time only enqueued_local_size is used, leaving local_size
unnecessary. In the end, payloadHeader has unused 20 bytes.

This commit enables short payload header on PVC platform.

Author: pkwasnie-intel

IGC/Compiler/CISACodeGen/helper.cpp

@@ -3032,9 +3032,6 @@ bool AllowShortImplicitPayloadHeader(const CodeGenContext *ctx) {
       return false;
   }
 
-  if (ctx->platform.getPlatformInfo().eProductFamily == IGFX_PVC)
-    return false;
-
   return ctx->platform.isCoreChildOf(IGFX_XE_HP_CORE);
 }