Fix broken links, make dddvb compile cleanly out-of-tree

[probutus]

Update outdated links to components within toolchain to enable building of octonet Project

• dvb-apps
• i2c tools
  Integrate dddvb into build process as internal package. This enables
• out-of-tree compilation with clean header structure
• minimize dependencies to underlying kernel
• resolve dependencies between octonet and tuners
• no need to have dedicated dddvb project checked out in same level as octonet
• easy update of octonet version
• adaption possible with standard patch prcess of buildroot

Build tested on target hardware, tuning and streaming works as with original structure, nand, ethernet, rtc and USB are working as intended.