hnbap: add UE Register Reject for pTMSIRAI identity

This is aimed at the ip.access nano3G femto cell, as it apparently feeds
whichever identification the UE sends through to HNBAP (TMSI+LAI, pTMSI+RAI),
instead of an IMSI as expected.

Sending a proper registration reject speeds up the response seen on the UE and
avoids needless waiting.

See the upcoming commit that enables accepting TMSI identities for further
detail.

Change-Id: I03b69613e6ddd8a08d9358ffc2f74954c231fd2c
1 file changed