OvmfPkg/CsmSupportLib: move PAM register addresses to IndustryStandard

OvmfPkg/CsmSupportLib: move PAM register addresses to IndustryStandard

* Introduce the PIIX4_PAM* and MCH_PAM* macros under
  "OvmfPkg/Include/IndustryStandard". These macros capture the PAM
  register offsets (in PCI config space) on the respective Memory
  Controller B/D/F, from the respective data sheets.

* Under IndustryStandard, introduce the PMC_REGISTER_PIIX4() macro for
  PIIX4. (For Q35, we already have DRAMC_REGISTER_Q35().) In both cases,
  the B/D/F is 0/0/0.

* Under CsmSupportLib, replace the "PAMRegOffset" field (UINT8) in the
  PAM_REGISTER_VALUE structure with "PAMRegPciLibAddress" (UINTN). The new
  field contains the return value of the PCI_LIB_ADDRESS() macro.

* Under CsmSupportLib, replace the "mRegisterValues440" elements as
  follows:

    REG_PAMx_OFFSET_440, ReadEnableData, WriteEnableData
    -->
    PMC_REGISTER_PIIX4 (PIIX4_PAMx), ReadEnableData, WriteEnableData

* Under CsmSupportLib, replace the "mRegisterValuesQ35" elements as
  follows:

    REG_PAMx_OFFSET_Q35, ReadEnableData, WriteEnableData
    -->
    DRAMC_REGISTER_Q35 (MCH_PAMx), ReadEnableData, WriteEnableData

* Under CsmSupportLib, update the register address calculations as follows
  (for all of PciOr8(), PciAnd8() and PciRead8()):

    PCI_LIB_ADDRESS (
      PAM_PCI_BUS,
      PAM_PCI_DEV,
      PAM_PCI_FUNC,
      mRegisterValues[Index].PAMRegOffset
      )
    -->
    mRegisterValues[Index].PAMRegPciLibAddress

* Under CsmSupportLib, remove the PAM_PCI_* and REG_PAM*_OFFSET_* macros.

Technically speaking, these changes could be split into three patches
(IndustryStandard macro additions, CsmSupportLib code updates,
CsmSupportLib macro removals). However, the patch is not big, and in this
case it is actually helpful to present the code movement / refactoring in
one step, for easier verification.

Cc: Aleksei Kovura <alex3kov@zoho.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Ref: https://bugs.launchpad.net/qemu/+bug/1715700
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Aleksei Kovura <alex3kov@zoho.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>