Increase sample time for ADC12 when using the internal temperature sensor, needed for F5529 at least.
Fix comments and calculations for number of samples per second for ADC10.
Add comments for ADC10 with calculations of number of samples per second.
Set flag ADC12SR for ADC12 since we are using less than 50ksps, to save power according to documentation
http://www.ti.com/lit/ug/slau406b/slau406b.pdf, page 7.