code cleanup:

1. remove unused macro/remove unnecessary included header file
2. for those values defined by PCI spec, use the naming of definition in IndustryStandard/Pci.h
3. use BITX macro in Base.h rather than define one by self.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8992 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Bus/Pci/EhciDxe/EhciReg.h

@@ -83,8 +83,6 @@ typedef enum {
   //
   // PCI Configuration Registers
   //
-  EHC_PCI_CLASSC          = 0x09,
-  EHC_PCI_CLASSC_PI       = 0x20,
   EHC_BAR_INDEX           = 0 /* how many bytes away from USB_BASE to 0x10 */
 }EHCI_REGISTER_OFFSET;