kernel config: Cleanup self-test module disabling

No reason to have complex version-dependent conditionals when the
question mark already handles this just as well.

Also add RUNTIME_TESTING_MENU setting which nicely disables all of this
on >= 4.16.

pkgs/os-specific/linux/kernel/common-config.nix

@@ -630,15 +630,17 @@ with stdenv.lib;
   FW_LOADER_USER_HELPER_FALLBACK? n
 
   # Disable various self-test modules that have no use in a production system
-  ${optionalString (versionOlder version "4.4") ''
-    ARM_KPROBES_TEST? n
-  ''}
-
+  # This menu disables all/most of them on >= 4.16
+  RUNTIME_TESTING_MENU? n
+  # For older kernels, painstakingly disable each symbol.
+  ARM_KPROBES_TEST? n
   ASYNC_RAID6_TEST? n
   ATOMIC64_SELFTEST? n
   BACKTRACE_SELF_TEST? n
   CRC32_SELFTEST? n
   CRYPTO_TEST? n
+  DRM_DEBUG_MM_SELFTEST? n
+  EFI_TEST? n
   GLOB_SELFTEST? n
   INTERVAL_TREE_TEST? n
   LNET_SELFTEST? n
@@ -647,41 +649,30 @@ with stdenv.lib;
   NOTIFIER_ERROR_INJECTION? n
   PERCPU_TEST? n
   RBTREE_TEST? n
+  RCU_PERF_TEST? n
   RCU_TORTURE_TEST? n
+  TEST_ASYNC_DRIVER_PROBE? n
+  TEST_BITMAP? n
   TEST_BPF? n
   TEST_FIRMWARE? n
+  TEST_HASH? n
   TEST_HEXDUMP? n
+  TEST_KMOD? n
   TEST_KSTRTOX? n
   TEST_LIST_SORT? n
   TEST_LKM? n
+  TEST_PARMAN? n
   TEST_PRINTF? n
   TEST_RHASHTABLE? n
+  TEST_SORT? n
   TEST_STATIC_KEYS? n
   TEST_STRING_HELPERS? n
   TEST_UDELAY? n
   TEST_USER_COPY? n
+  TEST_UUID? n
+  WW_MUTEX_SELFTEST? n
   XZ_DEC_TEST? n
 
-  ${optionalString (versionAtLeast version "4.13") ''
-    TEST_KMOD n
-  ''}
-
-  ${optionalString (versionOlder version "4.4") ''
-    EFI_TEST? n
-    RCU_PERF_TEST? n
-    TEST_ASYNC_DRIVER_PROBE? n
-    TEST_BITMAP? n
-    TEST_HASH? n
-    TEST_UUID? n
-  ''}
-
-  ${optionalString (versionAtLeast version "4.11") ''
-    DRM_DEBUG_MM_SELFTEST? n
-    TEST_PARMAN? n
-    TEST_SORT? n
-    WW_MUTEX_SELFTEST? n
-  ''}
-
   ${optionalString (features.criu or false)  ''
     EXPERT y
     CHECKPOINT_RESTORE y