Improve the COMPAT_VDSO check

CONFIG_COMPAT_VDSO disabled ASLR of vDSO only on X86_64 and X86_32.
On ARM64 this option has different meaning (see the mainline commit
7c4791c9efca8c105a86022f7d5532aeaa819125).

Thanks to @izh1979 for the idea

kconfig_hardened_check/checks.py

@@ -288,7 +288,6 @@ def add_kconfig_checks(l, arch):
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'ACPI_CUSTOM_METHOD', 'is not set')] # refers to LOCKDOWN
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_BRK', 'is not set')]
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'DEVKMEM', 'is not set')] # refers to LOCKDOWN
-    l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'BINFMT_MISC', 'is not set')]
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'INET_DIAG', 'is not set')]
     l += [KconfigCheck('cut_attack_surface', 'kspp', 'KEXEC', 'is not set')] # refers to LOCKDOWN
@@ -308,6 +307,10 @@ def add_kconfig_checks(l, arch):
              devmem_not_set)] # refers to LOCKDOWN
     l += [AND(KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is not set'),
               KconfigCheck('cut_attack_surface', 'kspp', 'LDISC_AUTOLOAD', 'is present'))]
+    if arch in ('X86_64', 'X86_32'):
+        l += [KconfigCheck('cut_attack_surface', 'kspp', 'COMPAT_VDSO', 'is not set')]
+              # CONFIG_COMPAT_VDSO disabled ASLR of vDSO only on X86_64 and X86_32;
+              # on ARM64 this option has different meaning
     if arch == 'ARM':
         l += [OR(KconfigCheck('cut_attack_surface', 'kspp', 'STRICT_DEVMEM', 'y'),
                  devmem_not_set)] # refers to LOCKDOWN