pkg/debian: Disable GDS mitigations to prevent invalid opcode issues

GDS mitigations disable the AVX instruction set if patched microcode is not present. Unfortunately, some programs depend on AVX (and do not check AVX presence), which leads to opcode errors if GDS mitigation is enabled.

So disable it for now.

pkg/debian/kernel/ubuntu.config

@@ -64,6 +64,14 @@ CONFIG_ACPI_I2C_OPREGION=y
 
 # CONFIG_VIDEO_ATOMISP_OV5693 is not set
 
+##
+## Disable GDS mitigation. Enabling GDS mitigations disables AVX
+## instructions, which causes a bunch of invalid opcode errors because
+## some programs assume AVX is present.
+##
+
+# CONFIG_MITIGATION_GDS_FORCE is not set
+
 ##
 ## Disable evbug. It's annoying and potentially even a security risk when
 ## posting kernel logs...