msm: ep_pcie: Enable update of pcie device and vendor id

Add code to enable update of pcie device id and vendor id as some devices
need it to enumerate correctly when connected to the host.

Signed-off-by: Siva Kumar Akkireddi <sivaa@codeaurora.org>
Change-Id: I8493aef8c5b741d578735c717d77bf5c18c65ea4