add symbols for the AOZ128xCI family of switchers

[florolf]

Add symbols for the AOZ128xCI family of switchers. Passes the linter with the exception of S4.2, which is caused by the flow-through style of powering DC-DC regulators that is also common in the KiCad standard library. Exemplary datasheet: http://aosmd.com/res/data_sheets/AOZ1280CI.pdf (all of them are linked in the symbols).

Compatibility with the standard library SOT-23-5 footprint has been proven both in manual assembly and with various manufacturing services.

Screenshot:

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All contributions to the kicad library must follow the KiCad library convention

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
• An example screenshot image is very helpful
• Ensure that the associated footprints match the official footprint library
  • A new fitting footprint must be submitted if the library does not yet contain one.
• If there are matching footprint PRs, provide link(s) as appropriate
• Check the output of the Travis automated check scripts - fix any errors as required
• Give a reason behind any intentional library convention rule violation.

[cpresser]

Thanks, this looks good!

• description, keywords and data-sheet (for all aliases)
• pin-types and names
• Footprint and FP-Filter (side-note: the text in your post is SOT-23-5. I assume that's a typo since datasheet and symbol both have sot-23-6)
• pin positions

We actually have different styles regarding the VIN pin even in recent commits to the library

• Add Sc4503 #2182 (Vin on the left)
• Added Texas Instruments TPS61252 switching regulator (tiny adjustable… #1988 (Vin on top)
• Your PR is pretty similar to NCP1529(Added NCP1529 #1906), which was just recently merged, so its good to go.