Add support for AT+CGMI and AT+CGMM

Added support for AT+CGMI and AT+CGMM commands. AT+CGMI gets
the AG manufacturer identifacation. AT+CGMM gets the AG
manufacturer model. The information is broadcasted as strings.

CRs-fixed: 844824
Change-Id: I9d53e378f6651ee0afd94b5525189c17cfeffa76
2 files changed