wcte13xp: New driver for digium's te13x product range

This patch adds support for Digium's new single span T1/E1 cards with built-in
octasic echo canceler.

PCI IDs:
d161:800a te133 - pci express
d161:800b te134 - pci

Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>