drm/amd/powerplay: fix spelling mistake "unknow" -> "unknown"

There is a spelling mistake in pr_warn message; fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/smu_v11_0.c

@@ -2024,6 +2024,6 @@ void smu_v11_0_set_smu_funcs(struct smu_context *smu)
 		vega20_set_ppt_funcs(smu);
 		break;
 	default:
-		pr_warn("Unknow asic for smu11\n");
+		pr_warn("Unknown asic for smu11\n");
 	}
 }