MdeModulePkg/PciBus: Refine EFI_PCI_ROM_IMAGE_MAPPING

The patch doesn't impact real functionality.
It only renames EFI_PCI_ROM_IMAGE_MAPPING to PCI_ROM_IMAGE,
and changes prototype of PciRomAddImageMapping so that
no explicit type cast is needed when calling this function.

It also removes unused field RomBase from PCI_IO_DEVICE structure.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>

MdeModulePkg/Bus/Pci/PciBusDxe/PciRomTable.h

@@ -1,7 +1,7 @@
 /** @file
   Set up ROM Table for PCI Bus module.
 
-Copyright (c) 2006 - 2009, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -23,8 +23,8 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
   @param Bus            Bus NO of PCI space.
   @param Dev            Dev NO of PCI space.
   @param Func           Func NO of PCI space.
-  @param RomAddress     Base address of OptionRom.
-  @param RomLength      Length of rom image.
+  @param RomImage       Option ROM buffer.
+  @param RomSize        Size of Option ROM buffer.
 
 **/
 VOID
@@ -34,8 +34,8 @@ PciRomAddImageMapping (
   IN  UINT8       Bus,
   IN  UINT8       Dev,
   IN  UINT8       Func,
-  IN  UINT64      RomAddress,
-  IN  UINT64      RomLength
+  IN  VOID        *RomImage,
+  IN  UINT64      RomSize
   );
 
 /**