sb,soc/intel: Drop OSYS from GNVS

The value should be set by OSPM using some combination of
_OSI() queris in the \_SB._INI() method.

To maintain previous behaviour with this commit, boards where
GNVS osys initialisation was removed now do the same in ASL.

Change-Id: Id4957b12a72fbf7fa988e7ff039e47abcc072e1c
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49353
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/acpi/dsdt_top.asl

@@ -8,5 +8,8 @@
 #include <vendorcode/google/chromeos/acpi/chromeos.asl>
 #endif
 
+/* Operating system enumeration. */
+Name (OSYS, 0)
+
 /* Power state (AC = 1) */
 Name (PWRS, One)