linux-phytec-ti

MAINTAINERS: Drop separate pseries entry

Paul is no longer acting as a separate maintainer for pseries, it is
handled along with the rest of powerpc. The URL no longer links anywhere
meaningful, so drop it also.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paul Mackerras <paulus@ozlabs.org>