[media] Add support for 'Digital Dual TV Receiver CTVDIGDUAL v2

[media] Add support for 'Digital Dual TV Receiver CTVDIGDUAL v2

Tested on a MIPSel box with 3.3.6 kernel
The kernel output when the device will be detected follows:
usbcore: registered new interface driver dvb_usb_it913x
it913x: Chip Version=01 Chip Type=9135
it913x: Remote propriety (raw) mode
it913x: Dual mode=3 Tuner Type=38
it913x: Chip Version=01 Chip Type=9135
usb 2-1: dvb_usb_v2: found a 'Digital Dual TV Receiver CTVDIGDUAL_V2' in cold state
usb 2-1: dvb_usb_v2: downloading firmware from file 'dvb-usb-it9137-01.fw'
it913x: FRM Starting Firmware Download
it913x: FRM Firmware Download Completed - Resetting Device
it913x: Chip Version=01 Chip Type=9135
it913x: Firmware Version 204147968
usb 2-1: dvb_usb_v2: found a 'Digital Dual TV Receiver CTVDIGDUAL_V2' in warm state
usb 2-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer
DVB: registering new adapter (Digital Dual TV Receiver CTVDIGDUAL_V2)
it913x-fe: ADF table value      :00
it913x-fe: Crystal Frequency :12000000 Adc Frequency :20250000 ADC X2: 00
it913x-fe: Tuner LNA type :38
usb 2-1: DVB: registering adapter 1 frontend 0 (Digital Dual TV Receiver CTVDIGDUAL_V2_1)...
usb 2-1: dvb_usb_v2: will pass the complete MPEG2 transport stream to the software demuxer
DVB: registering new adapter (Digital Dual TV Receiver CTVDIGDUAL_V2)
it913x-fe: ADF table value      :00
it913x-fe: Crystal Frequency :12000000 Adc Frequency :20250000 ADC X2: 00
it913x-fe: Tuner LNA type :38
usb 2-1: DVB: registering adapter 2 frontend 0 (Digital Dual TV Receiver CTVDIGDUAL_V2_2)...
usb 2-1: dvb_usb_v2: 'Digital Dual TV Receiver CTVDIGDUAL_V2' successfully initialized and connected
RC part not tested

Signed-off-by: Alessandro Miceli <angelofsky1980@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>