drm/i915/selftests: Increase timeout in i915_gem_contexts selftests

Like in the case of several other selftests, generating lots of requests
in a loop takes a bit longer with GuC submission. Increase a timeout in
i915_gem_contexts selftest to take this into account.
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210727031703.40395-2-matthew.brost@intel.com

drivers/gpu/drm/i915/gem/selftests/i915_gem_context.c

@@ -94,7 +94,7 @@ static int live_nop_switch(void *arg)
 			rq = i915_request_get(this);
 			i915_request_add(this);
 		}
-		if (i915_request_wait(rq, 0, HZ / 5) < 0) {
+		if (i915_request_wait(rq, 0, HZ) < 0) {
 			pr_err("Failed to populated %d contexts\n", nctx);
 			intel_gt_set_wedged(&i915->gt);
 			i915_request_put(rq);