ec/system76/ec: Hide ACPI device S76D

Hide the device so that Windows does not warn about a missing driver.

Tested on system76/lemp10:

- EC functionality remains functional on Linux 5.18.6 and Windows 10.
- Windows 10 does not report the device in Device Manager.

Change-Id: Iffcb873b85e077535d4de5806d01ba309f46c017
Signed-off-by: Jeremy Soller <jeremy@system76.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64700
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/ec/system76/ec/acpi/s76.asl

@@ -10,6 +10,8 @@
 Device (S76D) {
 	Name (_HID, "17761776")
 	Name (_UID, 0)
+	// Hide the device so that Windows does not warn about a missing driver.
+	Name (_STA, 0xB)
 
 	Method (RSET, 0, Serialized) {
 		Debug = "S76D: RSET"