MAINTAINERS, mailmap: Update address for Peter Hilber

Going forward, I will use another Qualcomm address,
peter.hilber@oss.qualcomm.com.

Map past contributions on behalf of Qualcomm to the new address as well.

Signed-off-by: Peter Hilber <peter.hilber@oss.qualcomm.com>
Message-Id: <20250826130015.6218-1-peter.hilber@oss.qualcomm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>