cpu/intel/haswell: Rework acpi/cpu.asl

Use acpigen_write_processor_cnot to implement notifications the CPU.
Generate PPKG in SSDT.

Change-Id: I126989e8737720f55f7ce113ff4e32bfe0f22620
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/29885
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/cpu/intel/haswell/acpi.c

@@ -339,6 +339,13 @@ void generate_cpu_entries(struct device *device)
 			acpigen_pop_len();
 		}
 	}
+
+	/* PPKG is usually used for thermal management
+	   of the first and only package. */
+	acpigen_write_processor_package("PPKG", 0, cores_per_package);
+
+	/* Add a method to notify processor nodes */
+	acpigen_write_processor_cnot(cores_per_package);
 }
 
 struct chip_operations cpu_intel_haswell_ops = {