[Feature][ZXW-163][ADC]Add Get ADC Voltage Demo

Only Configure:No
Affected branch:master
Affected module:ADC
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: Yes
Doc Update:Yes

Change-Id: Id40ed30e14b3b92c5690c5362243f300505b4d08
5 files changed