Fix missing pin 28 (VCAP1) in ADS1298_TQFP symbol from Analog_ADC l…

This pull request fixes the issue #1242 (closed)

I realized that the pin 28 is missing in ADS1298_TQFP symbol from Analog_ADC library.

Before fixing:

After fixing:

This pin is mandatory for TQFP package as can be seen in datasheet.

Regards, Otavio Augusto Gomes

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