bcm63xx: add support for Technicolor TG582n Telecom Italia branded

bcm63xx: add support for Technicolor TG582n Telecom Italia branded

Technicolor TG582n Telecom Italia branded a.k.a.
Telecom Italia ADSL2+ Wi-Fi N (AGTWI)
has the same PCB as the unbranded Technicolor TG582n with LEDs
connected to different GPIO PINs in active low configuration and
different LED names. It has a PCB similar to the OpenWrt's ADB P.DG A4001N1 one.

Hardware:
* Board ID: DANT-V
* SoC: Broadcom BCM6328 (rev b0) @ 320MHz, CPU BMIPS4350
* RAM DDR2: 64 Mbyte - EtronTech EM68B16CWQD-25H
* Serial flash: 16 Mbyte - Spansion FL 128SAIF00
* Ethernet: 4x Ethernet 10/100 baseT
* Wifi 2.4GHz: Broadcom Corporation BCM43227 Wireless Network Adapter (rev 30)
* LEDs: 2x Power, 1x ADSL, 2x Internet, 2x Wi-Fi, 2x Service, 4x ethernet
* Buttons: 1x Reset, 1x WPS (named WiFi/LED)
* UART: 1x TTL 115200n8, VCC GND TX RX, on J3 connector (short R62 and R63)

Installation via CFE:
* Stock CFE has to be overwritten with a generic 6328 one that can upload
  .bin images with no signature check (cfe6328_configured.bin)
* Connect a serial port to the board
* Stop the CFE boot process after power on by pressing enter
* Set static IP 192.168.2.10 and subnet mask 255.255.255.0
* Navigate to http://192.168.2.50/
* Upload the OpenWrt image file

PCB:   |GPIO:   |TG582n:          |AGTWI:

LED2R  |488(08) |red    Power     |red   Power
LED2G  |484(04) |green  Power     |green Power

LED10R |486(06) |                 |missing R85 end LED
LED13G |485(05) |green  Ethernet  |green ADSL

LED11R |494(14) |                 |red   Internet
LED14G |491(11) |green  Broadband |green Internet

LED5R  |487(07) |red    Internet  |red   Wi-Fi
LED5G  |481(01) |green  Internet  |green Wi-Fi

LED12R |498(18) |                 |red   Service
LED12G |499(19) |                 |green Service

LED6R  |482(02) |red    Wi-Fi     |missing R108 end LED
LED6G  |483(03) |green  Wi-Fi     |missing R107 end LED

LED7R  |490(10) |red    WPS       |missing R91 end LED
LED7G  |489(09) |green  WPS       |missing R92 end LED

LED4   |508(28) |ethernet port 4  |ethernet port 4
LED3   |507(27) |ethernet port 3  |ethernet port 3

LED9   |506(26) |ethernet port 2  |ethernet port 2
LED8   |505(25) |ethernet port 1  |ethernet port 1

SW3    |503(23) |key Reset        |key Reset

SW5    |504(24) |key WPS          |key Wi-Fi/LED

SW4    |495(15) |key Wi-Fi        |missing R127 end key

SW6    |493(13) |                 |missing R171 end key

SW1    |492(12) |                 |missing R1 end key

Signed-off-by: Daniele Castro <danielecastro@hotmail.it>
[DT fixes, base-files fixes and device variant]
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>