Add Dialog GreenPAK SLG46580/2/3 symbols

Add Dialog GreenPAK SLG46580/2/3 symbols.

Dialog Semiconductor (formerly Silego Technology) GreenPAK devices are described as a "NVM programmable device" containing a mix of digital components (such as LUTs, flip-flops, and counters) and analog components (such as comparators). The connection between these different blocks can be customized to produce different designs. These devices may be compared to FPGAs, CPLDs, or Cypress PSoC but do not actually fall under the any of those categories.

This PR adds symbols for the SLG46580/2/3 parts. These parts differ only in the number of LDOs present (SLG46580 has 4x LDOs with a max current of 150 mA each, SLG46582 has 2x LDOs with a max current of 300 mA each, SLG46583 has 1x LDO with a max current of 600 mA). They have the same footprint and share the same datasheet.

Corresponding footprint PR: kicad-footprints!2570

Datasheet: https://www.dialog-semiconductor.com/sites/default/files/slg46580_82_83r106_10252019.pdf

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