selftests: drv-net: pp_alloc_fail: add necessary optoins to config

Add kernel config for error injection as needed by pp_alloc_fail.py

Reviewed-by: Simon Horman <horms@kernel.org>
Fixes: 9da271f8 ("selftests: drv-net-hw: add test for memory allocation failures with page pool")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Link: https://patch.msgid.link/20251007232653.2099376-10-kuba@kernel.org


Signed-off-by: Paolo Abeni <pabeni@redhat.com>