added symbold for bq51050b

Created by: cyber-murmel

These are the two symbols for the bq5105xB High-Efficiency Qi v1.2-Compliant Wireless Power Receiver and Battery Charger.

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Thanks for creating a pull request to contribute to the KiCad libraries! To speed up integration of your PR, please check the following items:

• Provide a URL to a datasheet for the symbol(s) you are contributing
  • http://www.ti.com/lit/ds/symlink/bq51050b.pdf
• An example screenshot image is very helpful
  • VQFN
    • 
  • DSBGA
    • 
• Ensure that the associated footprints match the official footprint library
• If there are matching footprint PRs, provide link(s) as appropriate
  • VQFN
    • https://github.com/KiCad/kicad-footprints/pull/825
  • DSBGA
    • https://github.com/KiCad/kicad-footprints/pull/826
• Check the output of the Travis automated check scripts - fix any errors as required