x86: coreboot: Add a sysinfo driver

Create a sysinfo driver to avoid needing a custom checkboard()
function. With this the following information is printed when booting
from coreboot under QEMU:

   Model: Standard PC (i440FX + PIIX, 1996)
   Manufacturer: QEMU
   Prior-stage version: 4.21-885-g2a87ef1eca56
   Prior-stage date: 11/11/2023

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/x86/dts/coreboot.dts b/arch/x86/dts/coreboot.dts
index 0eb31ca..dfce7c2 100644
--- a/arch/x86/dts/coreboot.dts
+++ b/arch/x86/dts/coreboot.dts
@@ -45,4 +45,8 @@
 		bootph-some-ram;
 		compatible = "coreboot-fb";
 	};
+
+	sysinfo {
+		compatible = "coreboot,sysinfo";
+	};
 };