SecurityPkg: Add option to reset secure boot keys.

This commit add option which allows reset content of Secure Boot
keys and databases to default variables.

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
Reviewed-by: Sunny Wang <sunny.wang@arm.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>
Reviewed-by: Pete Batard <pete@akeo.ie>
Tested-by: Pete Batard <pete@akeo.ie> # on Raspberry Pi 4

SecurityPkg/VariableAuthenticated/SecureBootConfigDxe/SecureBootConfig.vfr

@@ -69,6 +69,12 @@ formset
     endif;
     endif;
 
+    text
+      help   = STRING_TOKEN(STR_SECURE_RESET_TO_DEFAULTS_HELP),
+      text   = STRING_TOKEN(STR_SECURE_RESET_TO_DEFAULTS),
+      flags  = INTERACTIVE,
+      key    = KEY_SECURE_BOOT_RESET_TO_DEFAULT;
+
   endform;
 
   //