OvmfPkg/SmmControl2Dxe: correct PCI_CONFIG_READ_WRITE in S3 boot script

OvmfPkg/SmmControl2Dxe: correct PCI_CONFIG_READ_WRITE in S3 boot script

EFI_BOOT_SCRIPT_PCI_CONFIG_READ_WRITE_OPCODE expects the PCI address to
access in UEFI encoding, not in edk2/PciLib encoding.

Introduce the POWER_MGMT_REGISTER_Q35_EFI_PCI_ADDRESS() macro, and with
it, store the ICH9_GEN_PMCON_1 register's address to the boot script in
UEFI representation.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>