drm/i915: Remove gen check before calling intel_rps_boost

It's been a while since gen6_rps_boost() [that only worked on gen6+] was
replaced by intel_rps_boost() that understood itself when rps was
active. Since the intel_rps_boost() is gen-agnostic, just call it.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728152219.1387-1-chris@chris-wilson.co.ukSigned-off-by: NRodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/i915/i915_request.c

@@ -1783,11 +1783,8 @@ long i915_request_wait(struct i915_request *rq,
 	 * but at a cost of spending more power processing the workload
 	 * (bad for battery).
 	 */
-	if (flags & I915_WAIT_PRIORITY) {
-		if (!i915_request_started(rq) &&
-		    INTEL_GEN(rq->engine->i915) >= 6)
+	if (flags & I915_WAIT_PRIORITY && !i915_request_started(rq))
 		intel_rps_boost(rq);
-	}
 
 	wait.tsk = current;
 	if (dma_fence_add_callback(&rq->fence, &wait.cb, request_wait_wake))