drm/xe: Store xe_hw_engine in xe_hw_engine_snapshot

A future patch will require gt and xe device structs, so here
replacing class by hwe.

Cc: Rodrigo Vivi <[e-mail]>
Cc: Matt Roper <[e-mail]>
Cc: Zhanjun Dong <[e-mail]>
Cc: Himal Prasad Ghimiray <[e-mail]>
Reviewed-by: Rodrigo Vivi <[e-mail]>
Signed-off-by: José Roberto de Souza <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/xe/xe_hw_engine.c

···
 		return NULL;
 
 	snapshot->name = kstrdup(hwe->name, GFP_ATOMIC);
-	snapshot->class = hwe->class;
+	snapshot->hwe = hwe;
 	snapshot->logical_instance = hwe->logical_instance;
 	snapshot->forcewake.domain = hwe->domain;
 	snapshot->forcewake.ref = xe_force_wake_ref(gt_to_fw(hwe->gt),
···
 	snapshot->reg.ring_eir = hw_engine_mmio_read32(hwe, RING_EIR(0));
 	snapshot->reg.ipehr = hw_engine_mmio_read32(hwe, RING_IPEHR(0));
 
-	if (snapshot->class == XE_ENGINE_CLASS_COMPUTE)
+	if (snapshot->hwe->class == XE_ENGINE_CLASS_COMPUTE)
 		snapshot->reg.rcu_mode = xe_mmio_read32(hwe->gt, RCU_MODE);
 
 	return snapshot;
···
 	drm_printf(p, "\tBBADDR: 0x%016llx\n", snapshot->reg.ring_bbaddr);
 	drm_printf(p, "\tDMA_FADDR: 0x%016llx\n", snapshot->reg.ring_dma_fadd);
 	drm_printf(p, "\tIPEHR: 0x%08x\n", snapshot->reg.ipehr);
-	if (snapshot->class == XE_ENGINE_CLASS_COMPUTE)
+	if (snapshot->hwe->class == XE_ENGINE_CLASS_COMPUTE)
 		drm_printf(p, "\tRCU_MODE: 0x%08x\n",
 			   snapshot->reg.rcu_mode);
 }

drivers/gpu/drm/xe/xe_hw_engine_types.h

···
 struct xe_hw_engine_snapshot {
 	/** @name: name of the hw engine */
 	char *name;
-	/** @class: class of this hw engine */
-	enum xe_engine_class class;
+	/** @hwe: hw engine */
+	struct xe_hw_engine *hwe;
 	/** @logical_instance: logical instance of this hw engine */
 	u16 logical_instance;
 	/** @forcewake: Force Wake information snapshot */