soc/intel/cnvi: Add CNIP Method

This method is used to provision the CNVi, and ensure
that it is in the correct state.

Intel document #559910 details this.

Change-Id: Id8a36a09c7beaf3ba8b29d3276bd9dc59420dab5
Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83713
Reviewed-by: Nicholas Sudsgaard <devel+coreboot@nsudsgaard.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/common/block/cnvi/cnvi.c

@@ -358,6 +358,31 @@ static void cnvw_fill_ssdt(const struct device *dev)
 		acpigen_pop_len();
 	}
 	acpigen_pop_len();
+
+/*
+ *	Method (CNIP, 0, NotSerialized)
+ *	{
+ *		If (^CNVW.VDID == 0xFFFFFFFF)
+ *		{
+ *			Return (Zero)
+ *		} Else {
+ *			Return (One)
+ *		}
+ *	}
+ */
+	acpigen_write_method("CNIP", 0);
+	{
+		acpigen_write_if_lequal_namestr_int("^CNVW.VDID", 0xffffffff);
+		{
+			acpigen_write_return_integer(0);
+		}
+		acpigen_write_else();
+		{
+			acpigen_write_return_integer(1);
+		}
+		acpigen_pop_len();
+	}
+	acpigen_pop_len();
 }
 
 static struct device_operations cnvi_wifi_ops = {