Revert "xhci: Preserve RsvdP bits in ERSTBA register correctly"

This reverts commit cfe314e9 which is
commit cf97c5e0 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I596d4ae4fc7ac5d4cd687b9bdfd32f7fea63c30f
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>