IntelFrameworkModulePkg KbDxe: Execute key notify func at TPL_CALLBACK

Current implementation executes key notify function in TimerHandler
at TPL_NOTIFY. The code change is to make key notify function
executed at TPL_CALLBACK to reduce the time occupied at TPL_NOTIFY.

The code will signal KeyNotify process event if the key pressed
matches any key registered and insert the KeyData to the EFI Key
queue for notify, then the KeyNotify process handler will invoke
key notify functions at TPL_CALLBACK.

Cc: Ruiyu Ni <Ruiyu.ni@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Jeff Fan <jeff.fan@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Ruiyu Ni <Ruiyu.ni@intel.com>

IntelFrameworkModulePkg/Csm/BiosThunk/KeyboardDxe/BiosKeyboard.h

@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
 
 This program and the accompanying materials
 are licensed and made available under the terms and conditions
@@ -223,11 +223,13 @@ typedef struct {
   // Buffer storing EFI_KEY_DATA
   //
   SIMPLE_QUEUE                                Queue;
+  SIMPLE_QUEUE                                QueueForNotify;
 
   //
   // Notification Function List
   //
   LIST_ENTRY                                  NotifyList;
+  EFI_EVENT                                   KeyNotifyProcessEvent;
   EFI_EVENT                                   TimerEvent;
   
 } BIOS_KEYBOARD_DEV;
@@ -554,6 +556,19 @@ BiosKeyboardTimerHandler (
   IN VOID         *Context
   );
 
+/**
+  Process key notify.
+
+  @param  Event                 Indicates the event that invoke this function.
+  @param  Context               Indicates the calling context.
+**/
+VOID
+EFIAPI
+KeyNotifyProcessHandler (
+  IN  EFI_EVENT                 Event,
+  IN  VOID                      *Context
+  );
+
 /**
   Reset the input device and optionaly run diagnostics