tpm_ibmvtpm: Update email address in maintainers list and ibmvtpm driver

Added myself as a maintainer for the IBM vtpm driver and removed myself
from the tpm maintainer list. Also, updated the tpm_ibmvtpm driver with
my current email address.

Signed-off-by: Ashley Lai <ashleydlai@gmail.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>