MdeModulePkg: Add EDKII_PCI_DEVICE_PPI definition

MdeModulePkg: Add EDKII_PCI_DEVICE_PPI definition

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3907

This commit introduces EDKII_PCI_DEVICE_PPI. The purpose of this PPI is
to provide a way of accessing PCI devices to drvice drivers such as
NvmExpressPei or AhciPei.

Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Maciej Czajkowski <maciej.czajkowski@intel.com>
Reviewed-by: Hao A Wu <hao.a.wu@intel.com>