mISDN: Added PH_* state info to tei manager.

Tei manager reports current layer 1 state on creation.
On state change it reports it to the socket interface.

Signed-off-by: Andreas Eversberg <andreas@eversberg.eu>
Signed-off-by: Karsten Keil <keil@b1-systems.de>
Signed-off-by: David S. Miller <davem@davemloft.net>