[Feature][ZXW-90]add gnss demo code.
Only Configure:No;
Affected branch:master;
Affected module:Gnss;
Is it affected on both ZXIC and MTK: only ZXIC;
Self-test: Yes;
Doc Update:Need

Change-Id: Ifc1b2a9a34e27de9123c387ae7751cc34dc5a42b
5 files changed