bcm63xx: drop USB LEDs for Technicolor TG582N / ADB P.DG A4001N

bcm63xx: drop USB LEDs for Technicolor TG582N / ADB P.DG A4001N

Remove the USB status red and green LEDs for
- ADB P.DG A4001N A-000-1A1-AX
- Technicolor TG582N
- Technicolor TG582N Telecom Italia

After having mounted an SMD socket for the flash memory for
JTAG reverse engineering, and so be able to easly swap between
OpenWrt and the stock FW, it turned out that the stock FW does
not light up the red and green USB LEDs exactly as I remembered.

Signed-off-by: Daniele Castro <danielecastro@hotmail.it>
[improve commit title]
Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>